UV-B辐射增强对20个大豆品种生长与生物量分配的影响

Influence of Enhanced UV -B Radiation on Growth and Biomass Allocation of Twenty Soybean Culti-vars

在大田栽培和自然光条件下,采用模拟UV-B辐射(280～315nm)方法,研究了UV-B辐射增强对20个大豆品种生长和生物量分配差异的影响。结果表明,UV-B辐射导致20个大豆品种叶片、根与茎、籽粒的生物量和总生物量降低,更多的生物量分配到籽粒。株高、节间长、节数对UV-B辐射增强响应具有品种间差异。株高和节间长对UV-B辐射响应具有一致性,呈极显著正相关,株高与节数无明显相关。20个大豆品种籽粒的粒径、百粒重对UV-B辐射均表现出不同程度的敏感性,其中20个品种的粒径降低程度达极显著水平,15个品种的百粒重降低程度达显著水平。根据响应指数(RI),耐性品种(RI≥-38.6)为:兰引20>云南97801>云南97929>云南97506>绿滚豆。敏感品种(RI≤-94.3)为:环县黄豆>云南97501>陇豆-1>土黄豆-1>灵台黄豆。

The effects of simulated enhanced UV -Bradiation(UV -B,280-315nm,5.31kJ·m -2)on the growth and biomass allocation of 20soybean cultivars were investigated under field natura l light conditions.The total biomass,the biomass of leaves,root,stemand grain all decreased under the stress conditions and the bio mass allocation to grain increased c ompared with the control.Genotypic differences were also observed in plant height,internode len gth and node number among the 20soybean cultivars under enhanced UV -B radiation The plant height and internode length showed sim ilar responses to UV -B radiation and there existed a significantly positive correlatio n between the two characters(r =0.579,P <0.01),while no significant correlation b etween plant height and node number was found(r =0.128).Grain diameter and 100-grain weigh t of 20soybean cultivars showed different sensitivity to UV -Bradiation.The g rain diameter of all the 20soybean cu ltivars decreased very significant ly and 15cultivars showed significant decrease in 100-grain weight.Based on response index(RI ),the tolerant cultivars(RI ≥-38.6)and the tolerant order were Lanyin 20>Yunnan 97801>Yunnan97929>Yunnan 97506>Lvgundou,whil e the sensitive cultivars(RI ≤-94.3)and the tolerant order were Huanxian huangdou >Yunnan 97501>Longdou -1>Yuhuangdou -1>Lingtai huangdou.