玉米杂交种灌浆期和收获期抗倒性差异及其与茎秆性状的相关性分析

采用3个田间整株抗倒伏指标(整株抗折力、整株抗弯强度、倒伏指数)和4个试验室抗倒性指标(茎秆第3节抗折力、第3节抗弯强度、穿刺强度、抗压强度)评估20个在黄淮海和东华北地区大面积种植的玉米杂交种在子粒灌浆期和收获期的抗倒性表现以及与6个植株茎秆性状(株高、穗位高、茎粗、节长、壁厚、茎秆密度)的简单相关和偏相关关系。结果表明,6个抗倒指标均呈现显著的品种间变异。与灌浆期相比,20个品种在收获期抗倒性均有不同程度下降,在灌浆期抗倒性表现相对较好的品种在收获期仍然表现较好。不同抗倒指标之间存在不同程度的相关性,大多数抗倒指标之间的相关度在灌浆期和收获期保持基本不变。不同抗倒指标与不同茎秆性状存在不同程度的相关,偏相关分析结果表明,茎秆穿刺强度是影响品种抗倒性的一个关键试验室指标。倒伏指数与田间抗折力有极显著负相关,与穗位高度呈显著正相关。

Comparing the Lodging Resistance Performance at Grain-filling and Harvesting and Its Correlation with Stalk Traits in Corn Hybrids

Three field lodging indicators(whole-plant snapping resistance, whole-plant flexural strength, and lodging index) and four laboratory lodging indicators(3^rd-internode snapping resistance, 3^rd-internode flexural strength, 3^rd-internode stalk crushing strength, and rind penetration resistance) were adopted to evaluate the lodging resistance performance of 20 commercial corn hybrids at two sampling stages:grain-filling and harvesting, and their variation and relative rank between the two stages; the simple and partial correlation among these indicators and their correlation with six stalk traits(PH-plant height, EH-ear height, CWT-culm wall thickness, SD-stem density, CD-culm diameter, InL-3^rd-internode length). Significant among-hybrid variation in all indicators was found in two sampling stages; the relative performance in lodging resistance drop significantly from grain-filling to harvest for all hybrids with variation among hybrids and those perform better in grain-filling generally also perform better at harvesting stage. The level and direction of correlation and partial correlation varied among indicators but the pattern hold from grain-filling to harvest. Stalk rind penetration resistance is a very important indictor underlying the two field indicators:whole-plant snapping resistance and whole-plant flexural strength, and its strength does not change when conditioned on each of the six stalk traits; the lodging index is negatively correlated with whole-plant snapping resistance and positively correlated with ear height.