摘要
为探寻遮阴对马铃薯光合和荧光特性及吸收光能分配的影响,本研究采用大田试验,以马铃薯不耐弱光品种‘丽薯6号’和耐弱光品种‘中薯20’为材料,出苗后用遮光率70%的黑色遮阳网进行遮阴处理(T),以自然光照为对照(CK),测定了遮阴30 d后马铃薯叶片的光合作用、光响应曲线、CO_2响应曲线、光诱导曲线和叶绿素荧光参数的变化。结果表明:1)遮阴后净光合速率(P_n)、气孔导度(G_s)、蒸腾速率(T_r)、最大净光合速率(P_(max))、光饱和点(LSP)、光补偿点(LCP)较CK显著下降;‘中薯20’的P_n、P_(max)、LSP较高,LCP和暗呼吸速率(R_d)较低。2)不同基因型CO_2响应参数无显著差异,但‘中薯20’的最大羧化速率(V_(cmax))和最大电子传递速率(Jmax)较高,CO_2补偿点(CCP)较低。3)高光诱导过程中,‘中薯20’反应较快,光合能力较强。4)初始荧光(F_o)、最大荧光(F_m)、最大光化学量子效率(F_v/F_m)较CK显著增加,PSⅡ实际光化学量子效率(?F/F_m′)、表观电子传递速率(ETR)和光化学猝灭系数(qP)较CK显著下降,非光化学猝灭系数(NPQ)呈增加趋势。5)非光化学热耗散(ФNPQ)和荧光耗散途径(Фf,d)比例显著增加,光化学猝灭耗散途径(ФPSⅡ)比例显著减少,主要以增加热耗散为主。遮阴后,耐弱光基因型‘中薯20’的NPQ和ФNPQ均高于不耐弱光的‘丽薯6号’,说明‘中薯20’的光合机构保护能力更强。综合分析表明,遮阴后耐弱光基因型马铃薯具有较高的净光合速率、较低的光补偿点、较低的CO_2补偿点、较快的光诱导反应速度和较高的非光化学热耗散能力。
With constant development of potato cultivation in winter agriculture fields in south China and in relay-intercropping systems in recent years,low light stress has been becoming the emerging limitation to potato development in these regions and it has increasingly gained considerable research attention.In order to explore the effects of low light stress on photosynthetic and chlorophyll fluorescent characteristics along with the distribution of absorbed light energy of low-light tolerant genotype potato,a field experiment was conducted with low-light sensitive potato cultivar‘Lishu6’and low-light tolerant potato cultivar‘Zhongshu20’.The experiment consisted of a shade treatment using black net that can filter70%of sunlight(T)and then a light treatment with full natural sunlight(CK)after seed emergence.The variations in photosynthesis,light and CO2response curves,light induced curve and chlorophyll fluorescence parameters of the different potato genotypes following30days of shade treatment were measured.The results following the shade treatment were as follows:1)the net photosynthetic rate(Pn),stomatal conductance(Gs),transpiration rate(Tr),maximum net photosynthetic rate(Pmax),light saturation point(LSP)and light compensation point(LCP)under T were significantly lower than those under CK.While Pn,Pmax and LSP of‘Zhongshu20’potato cultivar were relatively higher than those of‘Lishu6’potato cultivar,LCP and dark respiration rate(Rd)of‘Zhongshu20’potato cultivar were lower than those of‘Lishu6’potato cultivar.2)The parameters of CO2response curve were not significantly different between the shade and control treatments,but‘Zhongshu20’potato cultivar had higher maximum carboxylation rate(Vcmax),higher maximum electron transportation rate(Jmax)and lower CO2compensation point(CCP)than‘Lishu6’potato cultivar.3)Potato cultivar‘Zhongshu20’reacted quicker to high introduction rate and performed better in terms of photosynthetic capacity than potato cultivar‘Lishu6’.4)Compared with the control(CK),the increases of initial fluorescence(Fo),maximum fluorescence(Fm)and maximum photochemical quantum efficiency(Fv/Fm)were significantly higher in T treatments.Also reductions in actual photochemical quantum efficiency of PSⅡ(ΔF/Fm′),apparent electron transfer rate(ETR)and photochemical quenching coefficient(qP)were significantly higher in T treatments.Furthermore,there was an increasing trend in non photochemical quenching coefficient(NPQ).5)Compared with the control,the ratios of non-photochemical dissipation(ФNPQ)and fluorescence dissipation(Фf,d)pathways increased remarkably under shade treatment.The ratio of photochemical quenching pathway(ФPSⅡ)decreased significantly,makingФNPQ as the main pathway of dissipation.After shade treatment,the low-light tolerant potato genotype‘Zhongshu20’overall performance for NPQ andФNPQ was higher than the low-light sensitive potato genotype‘Lishu6’,suggesting that‘Zhongshu20’cultivar had more stronger photosynthetic apparatus protective capability.The above comprehensive analysis indicated that low-light tolerance genotype potatoes had relatively higher Pn,lower LCP and CCP,faster light induced reaction rate and higher non-photochemical dissipation capacity under shade conditions compared with that of low-light sensitive potato cultivar.
作者
李彩斌
郭华春
LI Caibin;GUO Huachun(Root &Tuber Crops Research Institute, Yunnan Agricultural University, Kunming 650201, China)
出处
《中国生态农业学报》
CSCD
北大核心
2017年第8期1181-1189,共9页
Chinese Journal of Eco-Agriculture
基金
国家马铃薯产业体系(CARS-10-P21)
云南省马铃薯种业重大专项(2013ZA007)资助~~
关键词
马铃薯
耐弱光
遮阴
光合特性
叶绿素荧光
Potato
Low-light tolerance
Shade condition
Photosynthetic characteristics
Chlorophyll fluorescence
作者简介
李彩斌, 主要研究方向为马铃薯栽培生理与育种。E-mail: ynlcb2015@126.com;通讯作者: 郭华春, 主要研究方向为薯类作物栽培生理与育种。E-mail: ynghc@126.com
