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### Characteristics and variation of winter rapeseed (Brassica napus L.) cultivars under high density

1. 1. Oil Crops Research Institute of Chinese Academy of Agriculture Sciences, Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430062, China; 2. Oil Station, Agricultural Bureau of Xishui County, Xishui 438200, China
• Online:2015-06-28 Published:2015-09-07

Abstract:

To better understand group advantage of rapeseed production and agronomic changes of cultivars under higher planting density (3.45×105 to 4.05×105 per hectare), yield and yield components from 22 newly registered cultivars in 4 regions were investigated in variety tirals 2013. The analysis was focused on correlation changes from cultivars registered in 2013 and 2001-2010 (in which rapeseed were planted at lower density). Results showed that average yield of the 22 cultivars was 2 861.25kg/hm2 and the average oil content was 44.88%. The average effective siliques per plant, seed per silique and thousand seed weight (TSW) were 280.52, 21.13 and 3.85g respectively. Coefficient of variation of effective siliques per plant was 0.21, which was higher than other 2 traits as seeds per silique and TSW. It indicated to be more variant among the cultivars. The coefficients was 0.68 between yield per plant and branch number. The coefficient was 0.79 between yield per plant and effective siliques per plant. Both correlations were highly significant. But the other 2 yield components (seeds per silique and TSW) had no significant correlation with yield per plant. Yield had no significant correlation with the above 3 yield components. Principal components analysis showed that 4 comprehensive factors contributed to 81.38%. Compared to cultivars from 2001-2010 planted at lower density, the average yield of cultivars from 2013 increased 10.61%. The effective siliques per plant decreased 29.08% with no difference of siliques per plant and TSW. The low correlation between yield and yield components might be resulted from high planting density.

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