长江中游南部油菜产区低产原因及育种对策

Causes of low yield and breeding countermeasures in rapeseed producing areas in the middle reaches of the Yangtze River

为明确长江中游南部地区影响油菜产量的关键气象因子,提高油菜育种效率,本文以长江中游2018-2020三年试验点的气象数据及参加国家冬油菜品种试验的106个油菜品种为基础数据进行分析。结果表明:相同油菜品种栽培条件下,南部地区的单产为2307.15 kg/hm^(2),比北部偏低25.28%,其中千粒重、每角粒数、有效分枝数和菌核病病情指数差异最大,分别降低16.09%、4.43%、9.19%和27.84%。通径分析表明南部地区油菜品种产量构成与北部显著不同,南部地区对小区产量直接作用大小依次为有效分枝数(0.2538)>千粒重(0.2887)>每角粒数(0.1469)>菌核病病情指数(-0.3981),北部地区对小区产量直接作用大小依次为全生育期(0.5798)>单株有效角果数(0.2128)>每角粒数(0.1624)>千粒重(-0.1630)。气象因子与产量回归分析表明,南部地区油菜产量与11月平均温度显著负相关,1月和3月昼夜温差显著正相关,11月和12月最低温显著负相关,2月和4月最低温极显著正相关,2月和4月降雨量显著负相关。从整个生育期看,长江中游南部地区主要影响油菜产量气象因子为昼夜温差、最低温度和降雨量。育种策略中,南部地区除了选育耐高温性和耐渍涝的油菜品种外,还应加强对千粒重、有效分枝数、每角粒数的选择,为进一步提高南部地区油菜单产提供理论依据。

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/hm^(2),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.