The results of characteristic comparison and principal component analysis showed that the major .characteristics of sesame varieties in Henan province were improved in the past decades. The sesame breeding works in th...The results of characteristic comparison and principal component analysis showed that the major .characteristics of sesame varieties in Henan province were improved in the past decades. The sesame breeding works in the province were focused on the collection and the screening of the native germplasms from 1950 to 1969 and the mean values of the variety characteristics were the lowest. In 1970s,the pedigree breeding was mainly conducted,which resulted in the release of varieties of various types with better traits. During 1980s,the hybridization breeding was carried out dominantly with the varieties possessing fine traits. Since 1990,there were no better varieties released. To make new progresses,it is essential to renew the breeding method and at the same time to introduce and create special germplasms to widen the genetic background.展开更多
Several groups in the USA have been working to de-velop a low chill apricot that would ripen its fruits veryearly in the season. Unfortunately, the cultivatcd apricothas been developed mainly from the high chilling Eu...Several groups in the USA have been working to de-velop a low chill apricot that would ripen its fruits veryearly in the season. Unfortunately, the cultivatcd apricothas been developed mainly from the high chilling Euro-pean group within the species Prunus armeniaca. Amongthe five groups within the apricot species, this is the mostrecently evolved and least variable (Bailey and展开更多
The Union for the Protection of New Varieties of Plants is abbreviated as UPOV. The Convention for the Protection of New Varieties of Plants has 1961/1972 Act ,1978 Act and 1991 Act. China is member of UPOV and its re...The Union for the Protection of New Varieties of Plants is abbreviated as UPOV. The Convention for the Protection of New Varieties of Plants has 1961/1972 Act ,1978 Act and 1991 Act. China is member of UPOV and its regulations of protection of new varieties of plants conform to 1978 Act. At present, there is big debate whether China accedes to 1991 Act. This paper mainly discussed advantages and possibilities that China accedes to 1991 Act, and concluded that it is highly desirable that China should consider acceding to 1991 Act in order to contribute to development of system on protection of new varieties of plants.展开更多
The development and wide application of genetic transformation for cotton improvement are restrained by the unresolved problem of genotype dependence in regeneration in vitro.High embryogenic and regenerative potentia...The development and wide application of genetic transformation for cotton improvement are restrained by the unresolved problem of genotype dependence in regeneration in vitro.High embryogenic and regenerative potential have been obtained for limited number of Coker type genotypes。展开更多
The fresh leaves and oven dried leaves from three varieties of black currant (Brodtrop,liangye,Risager)were analysed for the total contents of flavonoids by spectrophotometric methods in terms of rutin equivalent.In ...The fresh leaves and oven dried leaves from three varieties of black currant (Brodtrop,liangye,Risager)were analysed for the total contents of flavonoids by spectrophotometric methods in terms of rutin equivalent.In addition,antioxidant activities of different addition amounts of extracts of black currant (Brodtrop)leaves in lard were measured by the Oven-Storage Test,and compared with the synthetic antioxidants.The results showed the contents of the flavonoids were very rich in the leaves of three varieties from black currant.Among them the leaves of Brodtrop had the highest contents of flavonoids followed by liangye and Risager.The total contents of flavonoids in fresh leaves reach 231 70 mg/100 g,170 01 mg/100 g and 78 07 mg/100 g respectively.In the same circumstance the oven dried leaves were 397 82 mg/100 g,275 89 mg/100 g and 169 73 mg/100 g.The extracts of the leaves from Brodtrop exhibited strong antioxidant activities on lard,which increased with the addition amount of the flavonoid extracts.The antioxidant activities decreased in the order of 0 02% quercetin >0 02% BHT(butylated hydroxy toluene)>0 40% extracts>0 20% extracts>0 10% extracts>0 05% extracts>0 02% extracts>control.展开更多
Employing the pot experiment of the complete random block design with 6 replications,four varieties of japonica rice (Fujisaka 5,Honenwase,Akitakomachi and Taichung 65) were used to study the varietal differences in l...Employing the pot experiment of the complete random block design with 6 replications,four varieties of japonica rice (Fujisaka 5,Honenwase,Akitakomachi and Taichung 65) were used to study the varietal differences in leaf nitrogen content(LNC) and leaf area during mature period,their relation and effects to the ripening rate.The results showed that(1) thee were varietal differences in LNC at the heading stage and the LNC decrease rate during the matue period,the high LNC at the heading stage was related to the rapid LNC decrease.(2) There were two phases of the leaf area changing process during the mature period,first was the stable,and second was the decreased phase.There was varietal difference in the critical time of phase 1 and phase 2.The hign leaf area in the phase 1 was in relation to the rapid leaf area decrease in the phase 2.It was not found that there was relation between the leaf quality and quantity.(3)It wa unfavorable to the ripening rate for the high leaf area at the heading stage and the rapid decrease of the leaf area during the mature period.(4)It was put forward that the super high yield rice variety should possess the not very high leaf area and high LNC at the heading stage,slow senescence in the leaf area during the mature period.展开更多
We find that the word "English" is a mere generalization of many different types of the language, and we form the idea of "Englishes", or "varieties" or "sub-language" with the ...We find that the word "English" is a mere generalization of many different types of the language, and we form the idea of "Englishes", or "varieties" or "sub-language" with the English language. Among all, racial factor creates Black English and African Pidgin and others. They reconstitute the English grammar on the basis of the pidgin and gradually built up a special variety of their own. It is proved that none of language could conquer others. The only possibility that some one dominates others. English is the one. Chinese is different from English in branches and even families. As one variety, China English is not considered much like Black English, South-Asia English, etc.This thesis tries to study the nature and the cause of one of English variety through the explanation by the theory of interlanguage, fossilization, error analysis and transferring of language. China English is systematic and unstable.展开更多
Background： The cotton bollworm （Helicoverpa armigera） is one of cotton＇s most destructive insect pests in terms of yield and quality. Since 1997, China has grown commercially available transgenic Bacillus thuring...Background： The cotton bollworm （Helicoverpa armigera） is one of cotton＇s most destructive insect pests in terms of yield and quality. Since 1997, China has grown commercially available transgenic Bacillus thuringiensis （Bt） cotton. We aimed to investigate the variation in resistance of transgenic Bt cotton varieties to cotton bollworm in North China. Methods： Populations of cotton bollworm were monitored from 2008 to 2015 in environments where Bt cotton was planted adjacent to other non Bt crops. The study included 197 Bt cotton varieties planted in 42 counties/locations in three provinces （Hebei, Shandong and Henan） of North China, which were evaluated through field investigations, bioassays, and enzyme linked immunosorbent assays （ELISA）. Results： The average number of cotton bollworms never exceeded the action threshold （10 larvae per 100 cotton plants）, however, their number reached 19.55 per 100 cotton plants in 2011. The ratios of damaged plants to total Bt cotton stem tips, buds, and bolls was low except in 2010, when the ratios reached 1.82%, 2.09%, and 10.63%, respectively. The results of bioassay showed that the corrected mortality were higher at the second generation cotton bollworm stage than the third and fourth germination stages. Totally, Bt protein content declined sharply at the seedling stage from 2008 to 2015. Conclusions： This study indicated that almost all Bt cotton varieties were capable to effectively control the populations of cotton bollworm in North China.展开更多
Breeding for wilt resistance and its theoretical basis are primarily responsible for increases in cotton yield and fiber quality. Breeding for immunity is the most efficient method in our struggle with infectious dise...Breeding for wilt resistance and its theoretical basis are primarily responsible for increases in cotton yield and fiber quality. Breeding for immunity is the most efficient method in our struggle with infectious diseases.展开更多
A study was carried out to determine the relative susceptibility of six maize(Zea mays L.) varieties to maize weevil,Sitophilus zeamais Motschulsky(Coleoptera: Curculionidae). It was conducted at Department of Crop Pr...A study was carried out to determine the relative susceptibility of six maize(Zea mays L.) varieties to maize weevil,Sitophilus zeamais Motschulsky(Coleoptera: Curculionidae). It was conducted at Department of Crop Protection Laboratory,University of Ilorin, Nigeria at ambient temperature of 28±2℃ and 68%±3% relative humidity. Samples of the varieties were infestedwith five pairs of S. zeamais adults in their respective containers arranged in completely randomized design with three replications.Data were collected on moisture content, adult mortality, adult emergence, grain loss and grain damage. The index of susceptibilityand means of damage parameters were used to determine susceptibility of the maize varieties. The results showed that 2008 SYNEE W DT STR was highly resistant and 2004 TZE-W POP STR C4 was moderately resistant, while 2004 TZE-Y-POP STR C4,99 TZEE-Y-STR, EV99 QPM and TZE-Y-POP DT STR QPM C_0S1 were susceptible. Under artificial infestation, the weevils hadsignificantly longer survival period in the susceptible varieties than those in the resistant genotype. It could be concluded that thesusceptible varieties already released to farmers should be protected from maize weevil damage.展开更多
In Faranah Province （Guinea）, the ratio of supply and demand of corn is approximately 1 ： 2. The production is low and the deficit is covered by maize importation. This study was initiated in order to improve corn ...In Faranah Province （Guinea）, the ratio of supply and demand of corn is approximately 1 ： 2. The production is low and the deficit is covered by maize importation. This study was initiated in order to improve corn production by evaluating the effects of increasing doses of mineral fertilizers on the yield and economic profitability of corn. The experiment was conducted on a farm in Kamedankoude in a split plot with three replicates. Treatments included two varieties of maize （Perta and Kilissi113） and five doses of chemical fertilizers （D0=unfertilized control, Dl=300 kg NPKS＋200 kg urea. hm^2; D2=400 kg NPKS＋800 kg urea· hm^2; D3= 200 kg NPKS＋400 kg urea· hm^2 and D4=500 kg NPKS＋600 kg urea. hrn2）. The results showed that all the agronomic parameters increased with increasing dose of fertilizers, except for the number of ears per plant. The two varieties of corn tested produced similar yields. However, the profitability of mineral fertilizers decreased with increased doses and with value/cost ratio of 3. We recommended a mineral fertilizer dose of 300 kg NPKS ＋ 200 kg urea. The high prices of mineral fertilizers were often barriers to intensive maize cultivation, especially for low-income farmers. This study was a contribution to rational fertilization and adapted the socio-economic conditions of the region, with the background knowledge that most farmers in the regions earned low incomes.展开更多
Five F2 segregation populations, derived from crosses between the susceptible japonica cultivars （cvs.） Kongyul31 and donor cvs. Aichi Asahi （AA）, BL1, Digu, Pai-kan-tao （PKT） and Oryzica Llanos 5 （ORL5）, were...Five F2 segregation populations, derived from crosses between the susceptible japonica cultivars （cvs.） Kongyul31 and donor cvs. Aichi Asahi （AA）, BL1, Digu, Pai-kan-tao （PKT） and Oryzica Llanos 5 （ORL5）, were used to evaluate their natural resistance to blast in cold region. The field test of their blast resistance was conducted in 858 Farm, which showed that Aichi Asahi, BL 1 and Digu were highly resistant to either leaf blast or neck blast and could be used to develop molecular breeding by design, and genetic analysis indicated that the field resistance of Aichi Asahi, BLland Digu to leaf blast and neck blast was controlled by a single dominant gene, and the leaf blast and neck blast resistance in the donor cv. Pai-kan-tao was inherited as a single recessive gene, the neck blast resistance of the donor cv. Oryzica Llanos 5 was controlled by a single recessive gene while its leaf blast resistance was not controlled by this gene. These results suggested that five parental varieties positively contributed to resistance to either leaf blast or neck blast and could be used to expand the genetic germplasms resistant to blast in cold region using molecular assisted selection.展开更多
To reduce the risks associated with over-dependence on synthetic insecticides and ensure leguminous food security, an experiment was conducted to evaluate the potentials of integrating Piper guineense essential oil （...To reduce the risks associated with over-dependence on synthetic insecticides and ensure leguminous food security, an experiment was conducted to evaluate the potentials of integrating Piper guineense essential oil （PgEO） with cowpea varietal resistance in the control of cowpea seed beetle, Callosobruehus maculatus Fabricius. Four cowpea varieties （Sokoto, Drum, Oloyin and Gwallam） were studied. Data collected included oviposition, progeny emergence, Reproductive Efficiency （RE） and Percentage Seed Damage （PSD）. At first filial generation, numbers of eggs laid on Oloyin variety treated with 25 μL PgEO per 25 g cowpea seeds （2.15） were significantly （p〈0.05） lower than the values obtained in untreated cowpea （3.61） and hexane-treated seeds （3.07）. C. maculatus RE on Oloyin （33.73） was significantly （p〈0.05） lower than values obtained on other varieties （47.34-54.67） for seeds without PgEO; and were significantly greater than 0.00 observed on Oloyin seeds treated with 50 pL PgEO. PSD on Oloyin （6.63%） was significantly （p〈0.05） lower than the values obtained on Sokoto （10.04%） and Drum （9.79%） for seeds without PgEO, while there was no damage in Oloyin treated with 50 pL PgEO. Significantly （p〈0.05） lower F2 progeny emergence occurred on Oloyin （4.02） and Sokoto （4.71） compared with Drum （9.03） and Gwallam （6.07） from the untreated cowpea seeds. The results implied that application of PgEO to Oloyin gave better protection from infestation of C. maculatus than other varieties. Hence, combination of varietal resistance with PgEO for management ofbruchid could be an effective mean of improving cowpea food security.展开更多
Boehmeria nivea var.strigosa Zeng Y.Wu&Y.Zhao,a new variety of B.nivea(Urticaceae)from Southwest China,is here described based on evidence from morphology and molecular phylogeny.This new variety is mainly charact...Boehmeria nivea var.strigosa Zeng Y.Wu&Y.Zhao,a new variety of B.nivea(Urticaceae)from Southwest China,is here described based on evidence from morphology and molecular phylogeny.This new variety is mainly characterized by its green abaxial leaf blade,partly connate stipules,and densely patent strigose hairs on stems and potioles.The phylogenetic analysis based on rbc L,nrDNA and rbc L+nrDNA datasets,revealed that all individuals of B.nivea var.strigosa formed a monophyletic group.The conservation status of B.nivea var.strigosa is assessed as“Near Threatened”(NT)according to IUCN evaluation criteria.The discovery of this new variety is not only crucial for the taxonomy of ramie,but also provides reference for the exploration and utilization of ramie.展开更多
Background Bt technology has played significant role in controlling bollworms and increasing cotton yield in earlier days of its introduction,a subsequent decline in yield became apparent over time.This decline may be...Background Bt technology has played significant role in controlling bollworms and increasing cotton yield in earlier days of its introduction,a subsequent decline in yield became apparent over time.This decline may be attributed to various environmental factors,pest dynamics,or combination of both.Therefore,the present biophysical survey and questionnaire were designed to evaluate the impact of Bt cotton on bollworms management and its effect on reducing spray costs,targeting farmers with varied landholdings and educational backgrounds.Additionally,data on farmers'cultivated varieties and the prevalence of bollworms and sucking insects in their fields were recorded.Subsequently,about eleven thousand cotton samples from farmer fields were tested for Cry1Ac,Cry2Ab and Vip3A genes by strip test.Results In this analysis,83% of the farmers planting approved varieties believe that Bt technology control bollworms,while 17% hold contradictory views.Similarly,among farmers cultivating unapproved varieties,77% agree on effectiveness of Bt technology against bollworms,while 23% disagree.On the other hand,67% of farmers planting approved varieties believe that Bt technology does not reduce spray costs,while 33% agree with the effectiveness.Similarly,78% of farmers cultivating unapproved varieties express doubt regarding its role to reduce spray costs,while 22% are in favour of this notion.Differences in opinions on the effectiveness of Bt cotton in controlling bollworms and reducing spray cost between farmers planting unapproved and approved varieties may stem from several factors.One major cause is the heavy infestation of sucking insects,which is probably due to the narrow genetic variation of the cultivated varieties.Additionally,the widespread cultivation of unapproved varieties(21.67%)is also an important factor to cause different opinions on the effectiveness of Bt cotton.Conclusion Based on our findings,we propose that the ineffective control of pests on cotton crop may be attributed to large scale cultivation of unapproved varieties and non-inclusion of double and triple transgene technologies in country's sowing plan.On the basis of our findings,we suggest cotton breeders,regulatory bodies and legislative bodies to discourage the cultivation of unapproved varieties and impure seed.Moreover,the adoption of double and triple Bt genes in cottons with a broad genetic variation could facilitate the revival of the cotton industry,and presenting a promising way forward.展开更多
文摘The results of characteristic comparison and principal component analysis showed that the major .characteristics of sesame varieties in Henan province were improved in the past decades. The sesame breeding works in the province were focused on the collection and the screening of the native germplasms from 1950 to 1969 and the mean values of the variety characteristics were the lowest. In 1970s,the pedigree breeding was mainly conducted,which resulted in the release of varieties of various types with better traits. During 1980s,the hybridization breeding was carried out dominantly with the varieties possessing fine traits. Since 1990,there were no better varieties released. To make new progresses,it is essential to renew the breeding method and at the same time to introduce and create special germplasms to widen the genetic background.
文摘Several groups in the USA have been working to de-velop a low chill apricot that would ripen its fruits veryearly in the season. Unfortunately, the cultivatcd apricothas been developed mainly from the high chilling Euro-pean group within the species Prunus armeniaca. Amongthe five groups within the apricot species, this is the mostrecently evolved and least variable (Bailey and
文摘The Union for the Protection of New Varieties of Plants is abbreviated as UPOV. The Convention for the Protection of New Varieties of Plants has 1961/1972 Act ,1978 Act and 1991 Act. China is member of UPOV and its regulations of protection of new varieties of plants conform to 1978 Act. At present, there is big debate whether China accedes to 1991 Act. This paper mainly discussed advantages and possibilities that China accedes to 1991 Act, and concluded that it is highly desirable that China should consider acceding to 1991 Act in order to contribute to development of system on protection of new varieties of plants.
文摘The development and wide application of genetic transformation for cotton improvement are restrained by the unresolved problem of genotype dependence in regeneration in vitro.High embryogenic and regenerative potential have been obtained for limited number of Coker type genotypes。
文摘The fresh leaves and oven dried leaves from three varieties of black currant (Brodtrop,liangye,Risager)were analysed for the total contents of flavonoids by spectrophotometric methods in terms of rutin equivalent.In addition,antioxidant activities of different addition amounts of extracts of black currant (Brodtrop)leaves in lard were measured by the Oven-Storage Test,and compared with the synthetic antioxidants.The results showed the contents of the flavonoids were very rich in the leaves of three varieties from black currant.Among them the leaves of Brodtrop had the highest contents of flavonoids followed by liangye and Risager.The total contents of flavonoids in fresh leaves reach 231 70 mg/100 g,170 01 mg/100 g and 78 07 mg/100 g respectively.In the same circumstance the oven dried leaves were 397 82 mg/100 g,275 89 mg/100 g and 169 73 mg/100 g.The extracts of the leaves from Brodtrop exhibited strong antioxidant activities on lard,which increased with the addition amount of the flavonoid extracts.The antioxidant activities decreased in the order of 0 02% quercetin >0 02% BHT(butylated hydroxy toluene)>0 40% extracts>0 20% extracts>0 10% extracts>0 05% extracts>0 02% extracts>control.
文摘Employing the pot experiment of the complete random block design with 6 replications,four varieties of japonica rice (Fujisaka 5,Honenwase,Akitakomachi and Taichung 65) were used to study the varietal differences in leaf nitrogen content(LNC) and leaf area during mature period,their relation and effects to the ripening rate.The results showed that(1) thee were varietal differences in LNC at the heading stage and the LNC decrease rate during the matue period,the high LNC at the heading stage was related to the rapid LNC decrease.(2) There were two phases of the leaf area changing process during the mature period,first was the stable,and second was the decreased phase.There was varietal difference in the critical time of phase 1 and phase 2.The hign leaf area in the phase 1 was in relation to the rapid leaf area decrease in the phase 2.It was not found that there was relation between the leaf quality and quantity.(3)It wa unfavorable to the ripening rate for the high leaf area at the heading stage and the rapid decrease of the leaf area during the mature period.(4)It was put forward that the super high yield rice variety should possess the not very high leaf area and high LNC at the heading stage,slow senescence in the leaf area during the mature period.
文摘We find that the word "English" is a mere generalization of many different types of the language, and we form the idea of "Englishes", or "varieties" or "sub-language" with the English language. Among all, racial factor creates Black English and African Pidgin and others. They reconstitute the English grammar on the basis of the pidgin and gradually built up a special variety of their own. It is proved that none of language could conquer others. The only possibility that some one dominates others. English is the one. Chinese is different from English in branches and even families. As one variety, China English is not considered much like Black English, South-Asia English, etc.This thesis tries to study the nature and the cause of one of English variety through the explanation by the theory of interlanguage, fossilization, error analysis and transferring of language. China English is systematic and unstable.
基金supported by the project of China Agriculture Research System(CARS-15-20)
文摘Background： The cotton bollworm （Helicoverpa armigera） is one of cotton＇s most destructive insect pests in terms of yield and quality. Since 1997, China has grown commercially available transgenic Bacillus thuringiensis （Bt） cotton. We aimed to investigate the variation in resistance of transgenic Bt cotton varieties to cotton bollworm in North China. Methods： Populations of cotton bollworm were monitored from 2008 to 2015 in environments where Bt cotton was planted adjacent to other non Bt crops. The study included 197 Bt cotton varieties planted in 42 counties/locations in three provinces （Hebei, Shandong and Henan） of North China, which were evaluated through field investigations, bioassays, and enzyme linked immunosorbent assays （ELISA）. Results： The average number of cotton bollworms never exceeded the action threshold （10 larvae per 100 cotton plants）, however, their number reached 19.55 per 100 cotton plants in 2011. The ratios of damaged plants to total Bt cotton stem tips, buds, and bolls was low except in 2010, when the ratios reached 1.82%, 2.09%, and 10.63%, respectively. The results of bioassay showed that the corrected mortality were higher at the second generation cotton bollworm stage than the third and fourth germination stages. Totally, Bt protein content declined sharply at the seedling stage from 2008 to 2015. Conclusions： This study indicated that almost all Bt cotton varieties were capable to effectively control the populations of cotton bollworm in North China.
文摘Breeding for wilt resistance and its theoretical basis are primarily responsible for increases in cotton yield and fiber quality. Breeding for immunity is the most efficient method in our struggle with infectious diseases.
文摘A study was carried out to determine the relative susceptibility of six maize(Zea mays L.) varieties to maize weevil,Sitophilus zeamais Motschulsky(Coleoptera: Curculionidae). It was conducted at Department of Crop Protection Laboratory,University of Ilorin, Nigeria at ambient temperature of 28±2℃ and 68%±3% relative humidity. Samples of the varieties were infestedwith five pairs of S. zeamais adults in their respective containers arranged in completely randomized design with three replications.Data were collected on moisture content, adult mortality, adult emergence, grain loss and grain damage. The index of susceptibilityand means of damage parameters were used to determine susceptibility of the maize varieties. The results showed that 2008 SYNEE W DT STR was highly resistant and 2004 TZE-W POP STR C4 was moderately resistant, while 2004 TZE-Y-POP STR C4,99 TZEE-Y-STR, EV99 QPM and TZE-Y-POP DT STR QPM C_0S1 were susceptible. Under artificial infestation, the weevils hadsignificantly longer survival period in the susceptible varieties than those in the resistant genotype. It could be concluded that thesusceptible varieties already released to farmers should be protected from maize weevil damage.
文摘In Faranah Province （Guinea）, the ratio of supply and demand of corn is approximately 1 ： 2. The production is low and the deficit is covered by maize importation. This study was initiated in order to improve corn production by evaluating the effects of increasing doses of mineral fertilizers on the yield and economic profitability of corn. The experiment was conducted on a farm in Kamedankoude in a split plot with three replicates. Treatments included two varieties of maize （Perta and Kilissi113） and five doses of chemical fertilizers （D0=unfertilized control, Dl=300 kg NPKS＋200 kg urea. hm^2; D2=400 kg NPKS＋800 kg urea· hm^2; D3= 200 kg NPKS＋400 kg urea· hm^2 and D4=500 kg NPKS＋600 kg urea. hrn2）. The results showed that all the agronomic parameters increased with increasing dose of fertilizers, except for the number of ears per plant. The two varieties of corn tested produced similar yields. However, the profitability of mineral fertilizers decreased with increased doses and with value/cost ratio of 3. We recommended a mineral fertilizer dose of 300 kg NPKS ＋ 200 kg urea. The high prices of mineral fertilizers were often barriers to intensive maize cultivation, especially for low-income farmers. This study was a contribution to rational fertilization and adapted the socio-economic conditions of the region, with the background knowledge that most farmers in the regions earned low incomes.
基金Supported by the National Science and Technology Support Plan Project (2011BAD16B11)Heilongjiang Key Technologies R&D Program (GA09B106-2)Ph. D Programs Foundation of Northeast Agricultural University (2009RC09)
文摘Five F2 segregation populations, derived from crosses between the susceptible japonica cultivars （cvs.） Kongyul31 and donor cvs. Aichi Asahi （AA）, BL1, Digu, Pai-kan-tao （PKT） and Oryzica Llanos 5 （ORL5）, were used to evaluate their natural resistance to blast in cold region. The field test of their blast resistance was conducted in 858 Farm, which showed that Aichi Asahi, BL 1 and Digu were highly resistant to either leaf blast or neck blast and could be used to develop molecular breeding by design, and genetic analysis indicated that the field resistance of Aichi Asahi, BLland Digu to leaf blast and neck blast was controlled by a single dominant gene, and the leaf blast and neck blast resistance in the donor cv. Pai-kan-tao was inherited as a single recessive gene, the neck blast resistance of the donor cv. Oryzica Llanos 5 was controlled by a single recessive gene while its leaf blast resistance was not controlled by this gene. These results suggested that five parental varieties positively contributed to resistance to either leaf blast or neck blast and could be used to expand the genetic germplasms resistant to blast in cold region using molecular assisted selection.
文摘To reduce the risks associated with over-dependence on synthetic insecticides and ensure leguminous food security, an experiment was conducted to evaluate the potentials of integrating Piper guineense essential oil （PgEO） with cowpea varietal resistance in the control of cowpea seed beetle, Callosobruehus maculatus Fabricius. Four cowpea varieties （Sokoto, Drum, Oloyin and Gwallam） were studied. Data collected included oviposition, progeny emergence, Reproductive Efficiency （RE） and Percentage Seed Damage （PSD）. At first filial generation, numbers of eggs laid on Oloyin variety treated with 25 μL PgEO per 25 g cowpea seeds （2.15） were significantly （p〈0.05） lower than the values obtained in untreated cowpea （3.61） and hexane-treated seeds （3.07）. C. maculatus RE on Oloyin （33.73） was significantly （p〈0.05） lower than values obtained on other varieties （47.34-54.67） for seeds without PgEO; and were significantly greater than 0.00 observed on Oloyin seeds treated with 50 pL PgEO. PSD on Oloyin （6.63%） was significantly （p〈0.05） lower than the values obtained on Sokoto （10.04%） and Drum （9.79%） for seeds without PgEO, while there was no damage in Oloyin treated with 50 pL PgEO. Significantly （p〈0.05） lower F2 progeny emergence occurred on Oloyin （4.02） and Sokoto （4.71） compared with Drum （9.03） and Gwallam （6.07） from the untreated cowpea seeds. The results implied that application of PgEO to Oloyin gave better protection from infestation of C. maculatus than other varieties. Hence, combination of varietal resistance with PgEO for management ofbruchid could be an effective mean of improving cowpea food security.
文摘Boehmeria nivea var.strigosa Zeng Y.Wu&Y.Zhao,a new variety of B.nivea(Urticaceae)from Southwest China,is here described based on evidence from morphology and molecular phylogeny.This new variety is mainly characterized by its green abaxial leaf blade,partly connate stipules,and densely patent strigose hairs on stems and potioles.The phylogenetic analysis based on rbc L,nrDNA and rbc L+nrDNA datasets,revealed that all individuals of B.nivea var.strigosa formed a monophyletic group.The conservation status of B.nivea var.strigosa is assessed as“Near Threatened”(NT)according to IUCN evaluation criteria.The discovery of this new variety is not only crucial for the taxonomy of ramie,but also provides reference for the exploration and utilization of ramie.
基金supported by Punjab Agriculture Research Board,Grant numbers PARB No.890received research support from Punjab Agriculture Board。
文摘Background Bt technology has played significant role in controlling bollworms and increasing cotton yield in earlier days of its introduction,a subsequent decline in yield became apparent over time.This decline may be attributed to various environmental factors,pest dynamics,or combination of both.Therefore,the present biophysical survey and questionnaire were designed to evaluate the impact of Bt cotton on bollworms management and its effect on reducing spray costs,targeting farmers with varied landholdings and educational backgrounds.Additionally,data on farmers'cultivated varieties and the prevalence of bollworms and sucking insects in their fields were recorded.Subsequently,about eleven thousand cotton samples from farmer fields were tested for Cry1Ac,Cry2Ab and Vip3A genes by strip test.Results In this analysis,83% of the farmers planting approved varieties believe that Bt technology control bollworms,while 17% hold contradictory views.Similarly,among farmers cultivating unapproved varieties,77% agree on effectiveness of Bt technology against bollworms,while 23% disagree.On the other hand,67% of farmers planting approved varieties believe that Bt technology does not reduce spray costs,while 33% agree with the effectiveness.Similarly,78% of farmers cultivating unapproved varieties express doubt regarding its role to reduce spray costs,while 22% are in favour of this notion.Differences in opinions on the effectiveness of Bt cotton in controlling bollworms and reducing spray cost between farmers planting unapproved and approved varieties may stem from several factors.One major cause is the heavy infestation of sucking insects,which is probably due to the narrow genetic variation of the cultivated varieties.Additionally,the widespread cultivation of unapproved varieties(21.67%)is also an important factor to cause different opinions on the effectiveness of Bt cotton.Conclusion Based on our findings,we propose that the ineffective control of pests on cotton crop may be attributed to large scale cultivation of unapproved varieties and non-inclusion of double and triple transgene technologies in country's sowing plan.On the basis of our findings,we suggest cotton breeders,regulatory bodies and legislative bodies to discourage the cultivation of unapproved varieties and impure seed.Moreover,the adoption of double and triple Bt genes in cottons with a broad genetic variation could facilitate the revival of the cotton industry,and presenting a promising way forward.
