摘要
To learn about the phenological adaptation of <i><span style="font-family:Verdana;">Lactuca</span></i> <i><span style="font-family:Verdana;">georgica</span></i><span style="font-family:Verdana;"> Grossh., a wild relative of domesticated lettuce, we studied seed sampled accessions obtained from individual plants at 19 locations throughout six regions in Armenia, and from two natural populations in Dagestan (Russian Federation) collected as bulk samples. The effects of various vernalization treatments on time to bolting, flowering and seed production time were investigated during four successive years at different growth stages of </span><i><span style="font-family:Verdana;">L</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">georgica</span></i><span style="font-family:Verdana;"> plants. We demonstrate that low temperatures play a major role in stimulating the reproduction process of </span><i><span style="font-family:Verdana;">L</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">georgica</span></i><span style="font-family:Verdana;"> plants. Our results would suggest that for </span><i><span style="font-family:Verdana;">L</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">georgica</span></i><span style="font-family:Verdana;">: 1) There is an obligatory (or nearly so) vernalization requirement;2) Plant age, vernalization duration, and genotype of original sample have a role in bolting and flowering regulation;3) Some plants behaved as typical annuals, responding to vernalization treatment at the seedling stage, but, most did not;4) Four months of vernalization could be adequate to reach bolting in plants with a developed vegetative rosette, for most—but not all—samples;5) In order to find the best solution for stimulating the reproductive process of multiple genotypes, it seems that further study should focus on about 4 - 6 months of vernalization at 4°C applied to plants of about 10 - 22 months old vegetative rosettes, with controlled post-vernalization condition;6) </span><i><span style="font-family:Verdana;">L</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">georgica</span></i><span style="font-family:Verdana;"> germplasm could be used as a source for delayed bolting in breeding of domesticated lettuce varieties.</span>
To learn about the phenological adaptation of <i><span style="font-family:Verdana;">Lactuca</span></i> <i><span style="font-family:Verdana;">georgica</span></i><span style="font-family:Verdana;"> Grossh., a wild relative of domesticated lettuce, we studied seed sampled accessions obtained from individual plants at 19 locations throughout six regions in Armenia, and from two natural populations in Dagestan (Russian Federation) collected as bulk samples. The effects of various vernalization treatments on time to bolting, flowering and seed production time were investigated during four successive years at different growth stages of </span><i><span style="font-family:Verdana;">L</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">georgica</span></i><span style="font-family:Verdana;"> plants. We demonstrate that low temperatures play a major role in stimulating the reproduction process of </span><i><span style="font-family:Verdana;">L</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">georgica</span></i><span style="font-family:Verdana;"> plants. Our results would suggest that for </span><i><span style="font-family:Verdana;">L</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">georgica</span></i><span style="font-family:Verdana;">: 1) There is an obligatory (or nearly so) vernalization requirement;2) Plant age, vernalization duration, and genotype of original sample have a role in bolting and flowering regulation;3) Some plants behaved as typical annuals, responding to vernalization treatment at the seedling stage, but, most did not;4) Four months of vernalization could be adequate to reach bolting in plants with a developed vegetative rosette, for most—but not all—samples;5) In order to find the best solution for stimulating the reproductive process of multiple genotypes, it seems that further study should focus on about 4 - 6 months of vernalization at 4°C applied to plants of about 10 - 22 months old vegetative rosettes, with controlled post-vernalization condition;6) </span><i><span style="font-family:Verdana;">L</span></i><span style="font-family:Verdana;">. </span><i><span style="font-family:Verdana;">georgica</span></i><span style="font-family:Verdana;"> germplasm could be used as a source for delayed bolting in breeding of domesticated lettuce varieties.</span>
作者
Alex Beharav
Barbara Hellier
Alex Beharav;Barbara Hellier(Institute of Evolution, University of Haifa, Mt. Carmel, Haifa, Israel;USDA-ARS, Plant Germplasm Introduction and Testing Research Unit, Washington State University, Pullman, WA, USA)
