不同基因型抗虫棉的光合生产与叶源特征

以33B为对照,对早发型常规Bt棉鲁棉研17、鲁棉研21,晚发型Bt棉鲁棉研22,杂交Bt棉鲁棉研15、鲁棉研20进行了2年的种植和比较。早发型品种中前期干物质积累和叶面积增长快,但后期干物质积累慢、叶面积下降快,表现出明显的早发早熟和干旱年份易早衰的特点;晚发型品种前期干物质积累和叶面积增长慢,但后期增长快,表现出明显的晚发甚至贪青晚熟的特点。两个杂交棉品种表现出与早发型品种基本相同的生育规律,但中前期叶面积系数和干物质积累量显著高于其它供试品种。盛铃期以前,未见品种间功能叶光合速率的显著差异,但在干旱年份,早发型品种在始絮期功能叶的光合速率显著低于晚发型品种。早发型品种中后期的根冠比和功能叶含K量显著低于晚发型品种,而叶面积载荷量却显著高于晚发型品种。不同品种干物质产量和熟相的差异可能分别与叶面积系数大小和库源比例不同有关。

Photosynthetic Production and Leaf Source Parameters of Various Bt Cotton Genotypes

Three non-hybrid and two hybrid Bt cotton cultivars developed in Shandong province,as well as their control cultivar 33B,were grown and comparatively studied in 2002 and 2004.Results showed that three non-hybrid Bt cottons might be divided into an early-developed(ED) type(SCRC17 and SCRC21)and late-developed(LD) type(SCRC22)according to their earliness of maturity.In ED type,total biomass and leaf area per plant increased more quickly during early-and mid-season,and more slowly during late-season than those in the control.Plants of ED type exhibited enhanced earliness of maturity and even premature senescence in drought year.Contrasting to the ED type in accumulation of biomass and development of leaf area,LD type exhibited delayed earliness of maturity.Two hybrid cotton varieties(SCRC15 and SCRC 20) appeared similar to FD type in plant growth and development as well as earliness of maturity,but showed significantly higher increase in biomass and leaf area than all other varieties.No significant difference in net photosynthetic rate in functional leaves among genotypes before peak boll-setting stage,however,net photosynthetic rate in functional leaves of ED type was greatly inhibited relative to that of LD type at initial boll-opening stage,particularly in the drought year.Biomass ratio of root to the above ground,and K content in leaf blade in late-season were lower,but boll load per unit leaf area was higher,in FD type and hybrid cotton than in SD type.It is suggested that genotypic variation in accumulation of dry biomass and maturity performance might be correlated to the genotypic difference in leaf area and ratio of source to sink,respectively.