强优势杂交小麦产量结构模式的研究

A study on the yield structural model of strong heterosis for hybrid wheat

利用1999～2001年选用的9个性状差异较大的品种(系),按完全双列杂交(正交)组配成36个杂交组合,用一种新的分组法-Nair单性状水平分组法将杂交组合的各性状进行了分组,按产量分组结果对产量与各性状间的关系进行了研究,结果表明:随产量水平的升高单位面积穗数对产量的作用逐渐弱化,穗粒数对产量的作用逐渐增强,单位面积穗数与穗粒数间的相互作用构成限制产量的主要因素,千粒重对产量的作用较稳定;千粒重与单位面积穗数的负相关性较弱、与穗粒数无明显的相关性;在7500～9000kg/hm2水平下,产量结构模式为:504.0～607.5万穗/hm2,33.6～41.3粒/穗,35.7～42.3g/千粒重;在9000～10500kg/hm2水平下,产量结构模式为:525～645万穗/hm2,36～50粒/穗,37～45g/千粒重。

From 1999 to 2001,thirtysix hybrids were get from ninedilled crosses.A trail has been made with 36 varieties.Yield and yield components were divided into different groups by single characteristic method of Nair grouping.According to the result of yield grouping,the correlation between yield and yield components were studied.The results indicated:With the improvement of yield level,the effect of spikes to yield was decreased,the effect of kernels per head was improved,the relationship of spikes and kernels per head was the main element for confining yield,the effect of 1 000 kernel weight was stabilized.The negative correlation of 1 000 kernel weight and spikes was smaller;the correlation of 1 000 kernel weight and kernels per head was almost zero.And the structural model of hybrid wheat has been optimized with the yield level above 510 kilograms.At the yield level of 7 500 to 9 000 kg per hm2,the yield structural model was:5.04 to 6.075 million spikes per hm2,33.6 to 41.3 grains per head,35.7 to 42.3 g per 1 000 grain weight.At the yield level of 9 000 to 10 500 kg per hm2,the yield structural model was:5.25 to 6.45 million spikes per hm2,36 to 50 grains per head,37 to 45 g per 1 000 grain weight.