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(1)1957年,以东农47-1C(于哈尔滨自下种至成熟90—95天)、克霜(100—105天)、紫花四号(110—120天)、满仓金(125—130)、小金黄一号(135—140天)及丰地黄(145天左右)作为亲本,进行了八个组合的有性杂交。于F_1及F_2世代进行了单株成熟期及株高的调查记载,并按成熟期进行收获,混合脱粒。次年按组大小比例,随机自各成熟期组抽出一定的F_2种籽种下,记载F_3各组合植株的成熟期及一个组合的株高、种粒大小、开花期等性状。以上记载资料用来作为分析研究大豆杂交后代生育期遗传变异情况的资料。此外,还引用了1953年开始杂交的满仓金×南京早青豆组合的部分材料,以分析了解F_3以后世代品系内生育期变异程度的变化情况,及个体选择对杂交种生育期的作用。(2)试验的结果指出,F_1世代植物的生育期,介乎两亲本中间。F_2世代群体生育期的平均数,偏向晚熟亲本。F_3世代群体生育期的均数,亦近似两母本的平均数。F_3世代群体的生育期,并作近似常态的分布。各组合于F_2大都出现了亲本类型,并且出现了不同情况的超亲现象。这些情况说明,大豆生育期的遗传,是量性质的遣传,在杂交种的遗传机制上,呈现积累作用的现象,因而杂交后代,可以出现大量不同生育期的新类型。(3)F_2世代有显明的分离现象。于F_2世代按生育期组分别混合脱粒的材料,于F_3按组别种植,各组在生育期上显明地倾向F_2世代的生育期组别。来自F_2单株的F_3品系,表现更是如此,但是F_3品系内植株间的生育期,仍有一定程度的变异性,至F_4世代此变异性又形降低,至F_5世代变异性已降低至类似亲本,成为生育期整齐一致的品系。这说明,自F_2世代起,即可按生育期严加选择,并须定向选至F_5世代,才能形成于生育期方面的定型品系。(4)亲本的生育期,对杂交种后代生育期的遗传变异形势影响很大。杂交育种时,以用成熟期类似本地标准品种的亲本与略早的亲本品种杂交,或以成熟期略早于标准品种的亲本与略晚于标准品种亲本杂交,于F_2世代于生育期方面的选择余地才较大。如两亲本的成熟期均晚于本地标准品种,或一亲本类似标准品种,而另一亲本较晚熟,F_2世代于成熟期上,均难有选择的余地。大豆的正反交对大豆杂交后代生育期时遗传变异形势影响不大,于大豆杂交育种时,可不必强调。
(1) In 1957, Dongnong 47-1C (90-95 days after maturity in Harbin), cream (100-105 days), Zizhu IV (110-120 days) 130), Small Golden One (135-140 days), and Rehmannia glutinosa (about 145 days) were used as parents to carry out sexual crosses in eight combinations. The F_1 and F_2 generations were surveyed on the maturity and plant height of individual plants, harvested at the mature stage, and mixed and threshed. The next year according to the size of the group, randomly selected from each maturity group under a certain F_2 seeds recorded the F_3 combination of plant maturity and a combination of plant height, grain size, flowering and other traits. The above information is used to analyze the genetic variation of the sowing date of soybean crossbred. In addition, some materials of full-bloom × Nanjing early green bean hybrid which began hybridization in 1953 were used to analyze the changes of the variation degree of growth period in the generational lines after F_3 and the effect of individual selection on the growth period of hybrids. (2) According to the results of the experiment, the growth period of F_1 plants was between the parents. The average number of F_2 generations of the population growth period, tend to late-maturing parents. The average number of F_3 generation population growth period, also similar to the average number of two parents. F_3 generation groups of the reproductive period, and make the approximate normal distribution. Most of the combinations appeared in the F_2 parent type, and appeared in different circumstances super-progeny phenomenon. These facts show that the inheritance of soybean during its growth period is a kind of deportation of the quantitative nature, which shows the accumulation effect on the genetic mechanism of the hybrids. Therefore, a large number of new types of different growth stages can occur in the hybrids. (3) F_2 generations have obvious separation phenomenon. The materials which were mixed and threshed separately in the F_2 generation according to the growth period were planted in F_3 groups. Each group obviously tended to have the growth period of F2 generation in the growth period. The F_3 strain from F_2 strain was even more so, however, there was still a certain degree of variability in the growth period between F_3 lines. The variability of F_4 generation was also reduced to the same level as that of F_5 generation Parents, become a neat period of reproductive line. This shows that since the F_2 generation, you can choose strictly according to the growth period, and must be selected to F_5 generations in order to form the growth period of the stereotypes. (4) The growth period of the parents has a great influence on the genetic variation of the offspring of hybrids in the growth period. In hybrid breeding, the cross was crossed with a parental parent of a similar local standard at maturity or a parent with a slightly earlier maturity than that of a standard parent at a later stage of maturity, The choice is greater. For example, if the parents of the two parents mature later than the local standard or one of the parents is similar to the standard and the other parent is late, the F_2 generation will have little choice in the mature stage. The reciprocal cross of soybean has little effect on the genetic variation during the growth period of the progenies of soybean cross, and may not be emphasized in the crossbreeding of soybean.