干旱胁迫下玉米自交系穗部性状与耐旱性关系研究

Correlations between Ear Traits of Maize Lines and Drought Tolerance under Water - limited Condition

【目的】干旱是限制我国玉米生产的主,因素,研究干旱胁迫下玉米穗部性状与耐旱性的关系,为玉米耐旱性研究提供理论指导。【方法】通过抽雄吐丝期干旱胁迫的方法,对287份玉米自交系进行耐旱鉴定,调查穗长、穗粗、粒长、粒宽、粒厚、单穗干重、穗轴粗、粒重、百粒重、穗行数、行粒数等穗部性状,研究穗部性状与耐旱性的关系。【结果】相关分析发现单穗干重、穗长、穗行数、行粒数、粒长、粒重与玉米耐旱性存在极显著的相关性,穗粗和百粒重与玉米耐旱性存在显著相关性;通过对耐旱相关的穗部性状主成分分析,得到"产量"因子、"果穗行数"因子、"籽粒重量"因子、"轴部"因子、"果穗尺寸"因子,上述5个因子可以反映玉米自交系穗部的耐旱性;通过聚类分析获得耐旱性弱、适中、强的3种类群。【结论】单穗干重、穗长、穗行数、行粒数、粒长、粒重、穗粗和百粒重是十分重要的耐旱参考指标,在穗部耐旱性状中,对耐旱性的贡献大小依次为产量因素>果穗行数>籽粒重量>轴部因素>果穗尺寸,玉米在干旱胁迫下粒长、穗轴粗、百粒重较对照下降较少,穗长、穗粗、穗行数、粒重、单穗干重较对照略有增加,行粒数较对照下降适中,此类自交系耐旱性较强。

[ Objective] Maize production is often restricted by drought in China. In the present study, the relations between ear traits and drought tolerance under water - limited condition were investigated, which could provide the guidance to drought tolerance research. [ Method ] Traits of ear length, ear diameter, kernel length, kernel width, kernel thickness, dry weight per ear, cob diameter, kernel weight, kernel weight of 100, line number per ear, kernel number per line were investigated to study the relation between ear traits and drought tolerance for 287 maize lines by drought stress in flower stage. [ Result]Traits of dry weight per ear, ear length, line number per ear, kernel number per line, kernel length, kernel weight had 0.01 level significant correlation with drought tolerance, significant correlation with drought; the factors and ear diameter, kernel weight of 100 had 0. 05 level of ＂yield＂ , ＂ear lines＂, ＂per kernel weight＂, ＂cob＂, ＂earsize＂ which were reflected in ear drought tolerance were acquired with principal analysis; the drought tolerance groups of the weak, the moderate and the forceful were acquired with cluster analysis. [ Conclusion] The traits of dry weight per ear, ear length, line number per ear, kernel number per line, kernel length, kernel weight, ear diameter, kernel weight of 100 were very important traits to show drought tolerance; the contribution percentage about drought tolerance at ear traits were ＂yield＂ factor 〉 ＂ear lines＂ factor 〉 ＂per kernel weight＂ factor 〉 ＂cob＂ factor 〉 ＂ear size＂ factor; the group that under drought stress kernel length, cob diameter, kernel weight of 100 diminish a little and ear length, ear diameter, line number per ear, dry weight per ear, kernel weight had a little increase, and kernel number per line has moderate decrease which were thought of as forceful drought tolerance maize.