我国北部冬麦区小麦品种籽粒灌浆特性的研究

Grain Filling Properties of Winter Wheat Varieties in Northern Part of China

1992～1994年在北京对华北6省市以及国外近年来育成的一些冬小麦品种的籽粒灌浆特性进行了研究。在每亩40万穗左右、亩产400kg的条件下,决定籽粒产量的最重要性状是千粒重;而决定千粒重的主要因素是平均灌浆速率(AR)。山东品种的千粒重和AR在6省市为最高。采用Lo-gistic方程对籽粒灌浆过程进行拟合并求得有关灌浆参数。开花早的品种灌浆速率(R,R_(max))高,灌浆持续时间(T)较长,千粒重也高。相关分析表明,R和R_(max)与千粒重的相关系数分别为0.469和0.816;与T的相关系数分别为-0.948和-0.744。灌浆参数的逐步回归分析指出,决定千粒重的最重要参数是R_(max),其次是T。在21个代表性品种中以H88—65(饱满度为2级)的灌浆模式最优,其有关参数为:R=0.2284g/100粒/天,R_(max)=0.3015g/100粒/天,T=28.8天,千粒重=56.2g。从育种的角度考虑,北部冬麦区要增加粒重,以提高灌浆速率而不加长灌浆持续时间的策略较为有利。

In 1992-1994, nearly 500 varieties from Beijing, Hebei, Henan, Shandong, Shanxi, Shaanxi provinces and some other countries were studied for grain filling. Results showed that on the basis of 400 thousand spikes/mu(15 mu = l ha), which usually attains a yieldlevel of 400 kg/mu, 1000 grain weight was the first important trait for grain yield, and average grain filling rate was the most important trait for 1000 grain weight. Logistic equation was adopted for fitting the grain filling data for more than 70 varieties tested in this study. Varieties which flowered earlier had higher grain filling rate (R and Rmax), longer duration(T) and higher grain weight. A comparison of grain filling properties between 1993 and 1994 showed that the maximum grain filling rate and 1000 grain weight were higher in 1994, because the heading date was 5 days earlier this year. The correlation coefficients among R, Rmax vs. 1000 grain weight and R, Rmax vs. T were 0. 469 and 0. 816. and -0. 948 and -0. 744 , respectively. Multivariate regression analysis for the estimated parameters of grain filling properties indicated that Rmax was of first and T of second importance for determining the 1000 grain weight. On the basis of a comparison among 21 representative varieties, it was recognized that the parameters of grain filling for variety H88-65, i. e. R, 0. 2284 g/100 kernel/day; Rmax, 0. 3015 g/100 kernel/day; T, 28. 8 days; 1000 grain weight. 54. 4 g were the most desirable combination for Beijing area. In the breeding strategy for increased grain weight, stress should be focused on en-hansed grain filling rate and not on the prolonged duration of grain filling. Finally. the relationship among R , T . date of maturity , adjustion of developmental stages and grain weight. and the application of logistic equation to the breeding of higher grain weight were discussed. as judged from the ecological environments for winter wheat growing in the northern part of north China.