高粱种质种子萌发期耐冷性鉴定与综合评价

Identification and Comprehensive Evaluation of Cold Tolerance of Sorghum Germplasms During Seed Germination

高粱春季播种后突遇低温常使种子在土壤中“粉种”或霉烂导致萌发率、出苗率降低,为确保高粱能在更多温带地区尤其是在西北高寒地区推广利用。本研究以来自国内外60份高粱种质为材料,通过低温胁迫(4℃)和常温(25℃,设为对照)两种处理方式对参试种质种子萌发期进行耐冷性鉴定,测定5个性状指标,并用加权隶属函数值、综合耐冷系数、加权耐冷系数等3种综合评价法对其耐冷性进行评价和分类。结果表明,在低温胁迫下,高粱种质5个测定指标均出现下降,且经低温处理的60个种质与对照相比性状之间差异显著,种质耐冷性存在较大差异。对测试指标耐冷系数相关性分析表明,除发芽率与胚芽长和胚根长相关性不显著以及胚根鲜重与胚芽长大小相关性不显著外,其余指标均存在一定程度的相关性。根据3种综合耐冷评价方法筛选出高耐冷型材料2份(平凉1 B、晋草10号),敏感型材料5份(泰斯、89105(R)、扫帚高粱、NTJ-2(IS 33892)、J 101-R)。

Low temperature after sorghum sowing in spring often makes seeds“powdery”or mildew in the soil,leading to lower germination rate and seedling emergence rate.To ensure that sorghum can be popularized and utilized in more temperate regions,especially in the alpine region of northwest China,the 60 sorghum germplasms from home and abroad were treated with low temperature(4℃)and normal temperature(25℃,as the control)in this study.And,the cold tolerance of the germplasms were evaluated and classified by weighted membership function value,comprehensive cold tolerance coefficient and weighted cold tolerance coefficient.The results showed that all the 5 indexes of the germplasms decreased under low temperature stress,and the 60 germplasms treated by low temperature had significant differences in traits and cold tolerance compared with the control.The correlation analysis of cold tolerance coefficient of tested indexes showed that there was a certain degree of correlation except that there was no significant correlation between germination rate and germ length or radicle length,and between radicle fresh weight and radical length.Finally,two highly cold-tolerant sorghum materials(Pingliang 1 B and Jincao 10)and four cold-sensitive materials(Taisi,89105(R),Saozhou,NTJ-2(IS 33892),J 101-R)were screened by three comprehensive cold tolerance evaluation methods.