Causes of low yield and breeding countermeasures in rapeseed producing areas in the middle reaches of the Yangtze River
In order to clarify the key meteorological factors affecting rapeseed yield in the southern part of the middle reaches of the Yangtze River and improve the efficiency of rapeseed breeding,the meteorological data of the three-year test sites in the middle reaches of the Yangtze River from 2018 to 2020 and the 106 rapeseed varieties participating in the national winter rapeseed variety experiment were analyzed in this paper.The results showed that,under the same cultivation conditions of rapeseed varieties,the yield per unit area in the southern region was 2307.15 kg/hm2,which was 25.28%lower than that in the northern region,among them,the 1000-grain weight,the number of seed per pod,the effective branch number and the disease index of sclerotiorum were the most different,which decreased by 16.09%,4.43%,9.19%and 27.84%respectively.Pathway analysis showed that the yield com-position of rapeseed varieties in the southern region was significantly different from that in the north,Path analysis showed that the yield composition of rape varieties in southern China was significantly different from that in north-ern China.The direct effect of southern on yield per piot was effective branch number(0.2538)>1000-seed weight(0.2887)>number of seeds per corner(0.1469)>disease Index of Sclerotiorum(-0.3981),while the direct effect of northern on yield per piot was whole growth period(0.5798)>effective pod per plant(0.2128)>number of seeds per pod(0.1624)>1000-seed weight(-0.1630).Regression analysis of meteorological factors and yield showed that the yield of rapeseed in southern was significantly negatively correlated with the average temperature in November,the diurnal temperature difference in January and March was positively correlated,the lowest temperature in Novem-ber and December was negatively correlated,the lowest temperature in February and April was extremely positively correlated,and the rainfall in February and April was negatively correlated.From the whole growth period,the main meteorological factors affecting rapeseed yield in the southern part of the middle reaches of the Yangtze River were the diurnal temperature difference the lowest temperature and rainfall.In the breeding strategy,in addition to breed-ing rapeseed varieties with high temperature tolerance and waterlogging tolerance,the southern region should also strengthen the selection of 1000-grain weight,effective branch number and number of grains per horn,so as to pro-vide theoretical basis for further improving the yield of rapeseed in the southern region.
winter oilseed rapethe southern reaches of the Yangtze Rivermeteorological factorsagronom-ic traits
万方数据
维普
