白菜型冬油菜抗倒伏性评价及其与株型性状的相关分析

于2018—2019年以44份不同抗倒性的白菜型冬油品系(种)为试材,依据改良倒伏系数(ILC)法对其抗倒伏性进行聚类分析和评价,探讨白菜型冬油菜株型、茎秆力学特性、干物质积累量等对其倒伏性的影响。结果表明:依据ILC可将白菜型冬油菜参试材料聚为3类:Ⅰ类为强抗倒性材料,包含2个品系(种);Ⅱ类为中等抗倒性材料,包含15个品系(种);Ⅲ类材料抗倒性最弱,包含27个品系(种)。聚类结果与田间倒伏分级结果基本吻合,两者呈极显著正相关(r=0.452~(**)),表明利用ILC评价白菜型冬油菜的抗倒伏性具有可靠性。与Ⅱ类、Ⅲ类材料相比,抗倒性强的Ⅰ类材料株高显著变矮,重心高度显著降低,其平均株高和重心高度比倒伏Ⅲ类材料分别降低19.8 cm和17.8 cm。白菜型冬油菜茎秆抗折力在三类材料间均存在显著差异,抗倒伏Ⅰ类参试材料平均茎秆抗折力是Ⅲ类材料的2.59倍。白菜型冬油菜倒伏系数与株高(r=0.346~*)、地上部鲜质量(r=0.344~*)、重心高度(r=0.579~*)呈显著正相关,与茎秆抗折力(r=-0.518~*)呈显著负相关。与Ⅱ类、Ⅲ类材料相比,Ⅰ类参试材料根长增长38%～41%,根鲜质量增大71%～102%,分枝部位降低32%～44%,一次分枝数增加10%左右、单株角果数增加30%～38%、角果长度增长1%左右、每角粒数增加11%～14%,千粒重增加21%～23%。白菜型冬油菜参试材料抗倒伏性存在显著差异,植株高度、重心高度、地上部鲜质量、茎秆抗折力等是影响其抗倒伏性的关键因素,株高较小、重心高度较低、茎秆抗折力大的白菜型冬油菜品种更高产抗倒伏。

Evaluation of lodging resistance and correlation analysis with plant architecture in winter rapeseed

In 2018-2019, 44 high|generation hybrid lines of winter rapeseed (Brassica rapa L.) with different lodging resistance were used as test materials to provide genetically improving lodging resistance in winter rapeseed (Brassica rapa L.). Their lodging resistance was clustered and evaluated by the improved lodging coefficient (ILC) method. The impacts on the lodging resistance of winter rapeseed including plant form, stem mechanical properties and plant weight were discussed. The results showed that the tested winter rapeseed materials could be split into three forms according to the improved lodging coefficient. Type I, high resistance to lodging, including 2 lines, type II with moderate resistance to lodging, including 15 lines, and type III with the lowest resistance to lodging, including 27 lines. The findings of the clustering were largely consistent with the results of the field classification of lodging, with a strong positive correlation between them (r=0.452^**). The improved coefficient of lodging was accurate and reliable in assessing the resistance of winter rapeseed lodging. The plant height and center of gravity height of type I materials with high lodging resistance decreased substantially compared to type II and III materials and the mean plant height and center of gravity decreased by 19.8 cm and 17.8 cm, respectively. Among the three types of winter rapeseed (Brassica rapa L.) materials, there were substantial variations in stem breaking|resistant strength, and the average stem breaking|resistant strength of category I materials was 2.59 times higher than that of type III materials. The lodging coefficient of the winter rapeseed (Brassica rapa L.) was positively correlated with plant height (r=0.346^*), new aerial component weight (r=0.344^*) and center of gravity height (r=0.579^*) correlated negatively with break|resistant power (r=-0.518^*). Compared with the materials of class II and class III, the root length of the test materials of class I increased by 38% to 41%, the fresh root weight increased by 71% to 102%, the branch position decreased by 32% to 44%, and the number of branches at a time increased about 10%, the number of siliques per plant increased by 30% to 38%, the length of siliques increased by about 1%, the number of grains per horn increased by 11% to 14%, and the thousand|grain weight increased by 21% to 23%. There were significant differences in the lodging resistance of the tested materials of winter rapeseed (Brassica rapa L.). The plant height, the height of the center of gravity, the fresh weight of the above ground, and the stalk resistance were the key factors affecting the lodging resistance. The winter rapeseed (Brassica rapa L.) with smaller plant height, lower center of gravity, and greater stalk bending resistance had higher yield and lodging resistance.