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1982—83和1983—84两年度分别利用由4×4和5×4不完全双列杂交配制的杂种 F_1及相应亲本,采用相关和通径分析等方法在田间稀条播条件下研究了 T 型杂种小麦各产量构成因素的优势与产量优势表现的关系。供试杂种产量杂种优势最高这30%,但年份之间有一定变化。千粒重普遍表现明显的杂种优势,穗拉数往往表现负优势,穗数优势的表现则很不一致。产量优势是其构成因素的优势相互补偿和积累的结果。各产量因素的优势对产量优势的贡献大小取决于各因素的直接通径系数和优势幅度两方面.穗数对产量的作用明显大于穗粒数和千粒重,穗数优势对产量优势有举足轻重的作用.千粒重的直接效应虽然较小,但因其优势幅度较大,对产量优势的形成仍有重要贡献.穗粒数的负优势主要是由于每小穗粒数的负优势所造成的.而每小穗粒数的负优势则主要是由于杂种育性恢复度不够高所造成的.
In 1982-83 and 1983-84, F1 hybrids and their corresponding parents, which were made by 4 × 4 and 5 × 4 incomplete diallens respectively, were used to study the effects of T type Relationships between the Advantages of Yield Components and Yield Superiority in Hybrid Wheat. Heterosis hybrids yield the highest 30%, but there are some changes between years. Thousand grain weight generally showed obvious heterosis, spike pull number often showed negative advantage, the spike number advantage is very inconsistent. Yield advantage is the result of the mutual compensation and accumulation of the advantages of its constituent factors. The contribution of each yield factor to yield superiority depends on both the direct path coefficient and the dominant amplitude of each factor.The effect of panicle number on yield is obviously greater than that of spike grain and 1000-grain weight. The advantage of panicle number plays a decisive role in yield superiority Although the direct effect of 1000-grain weight is small, it still has an important contribution to the formation of yield superiority due to its large range of advantages.The negative advantage of grain-per-spike is mainly due to the negative superiority of grain number per spikelet The negative predominance of spikelet number was mainly due to the low level of hybrid fertility restoration.