不同播种量对紫花苜蓿种子产量及构成因素的影响

Effects of different seeding rates on seed yield and components of alfalfa

为探讨宁夏半干旱区紫花苜蓿(Medicaco sativa)种子田高效生产的最佳播种量,采用单因素随机区组设计,研究不同播种量(S_(1):1.2 kg·hm^(-2),S_(2):1.8 kg·hm^(-2),S_(3):2.4 kg·hm^(-2),S_(4):3.0 kg·hm^(-2),S_(5):3.6 kg·hm^(-2))对紫花苜蓿种子生产性能和构成因素的影响。结果表明,播种量对紫花苜蓿株高、一级分枝数、每生殖枝花序数、每花序小花数、每花序结荚数、单位面积生殖枝条、每荚种子数、千粒重、实际种子产量和表现种子产量均有显著影响(P<0.05),其中单位面积生殖枝数、每生殖枝花序数、每花序结荚数、每荚种子数及千粒重均在S_(4)播量下达到最高,分别为177.09、23.35、12.56、6.16和1.88 g;株高和每花序小花数在S_(2)播量下达到最大,分别为87.81 cm和18.18;以上指标均随播种量的增加呈先增加后降低趋势。表现种子产量和实际种子产量均在S4处理下最大,分别为5993.39和630.68 kg·hm^(-2),较S_(1)处理提高了180.25%和38.41%。相关性分析表明,每生殖枝花序数与每花序小花数和种子产量间均极显著正相关(P<0.01)。主成分分析显示,每生殖枝花序数和实际种子产量的贡献率最大,每荚种子数次之,株高的贡献率最小,综合排名由高到低为S_(4)>S_(3)>S_(2)>S_(5)>S_(1)。建议在宁夏半干旱区紫花苜蓿种子田生产的最佳播种量为3.0 kg·hm^(-2)。

In order to determine the optimum sowing rate of alfalfa seed field in a semi-arid area of the Ningxia region,a single factor randomized block design was used to study the effects of different sowing rates(S_(1):1.2 kg·ha^(-1),S_(2):1.8 kg·ha^(-1),S_(3):2.4 kg·ha^(-1),S_(4):3.0 kg·ha^(-1),S_(5):3.6 kg·ha^(-1))on alfalfa seed production performance and composition factors.Plant height,number of primary branches,number of inflorescences per reproductive branch,number of spikelets per inflorescence,number of pods per inflorescence,number of reproductive branches per unit area,number of seeds per pod,1000-grain weight,actual seed yield,and the performance seed yield of alfalfa were significantly affected by sowing rate(all P<0.05).The number of reproductive branches per unit area,number of inflorescences per reproductive branch,number of pods per inflorescence,number of seeds per pod,and the 1000-grain weight were the highest under S_(4) sowing rate(177.09,23.35,12.56,6.16,and 1.88 g,respectively).Plant height and number of spikelets per inflorescence reached their maximum under S_(2) sowing rate(87.81 cm and 18.18,respectively).The above indices initially increased and then decreased with increasing seeding rate.Seed and actual seed yields were the highest under S_(4) treatment(5993.39 and 630.68 kg·ha^(-1),respectively),representing respective increases of 180.25% and 38.41% compared with S_(1) treatment.Correlation analysis revealed that the number of inflorescences per reproductive branch was positively correlated with the number of spikelets per inflorescence and seed yield(S_(4)>S_(3)>S_(2)>S_(5)>S_(1)).The findings suggest that the best sowing rate for alfalfa seed production in the semiarid area of Ningxia is 3.0 kg·ha^(-1).