摘要
将正常品种与无花瓣亲本杂交,正反交F_1代中有瓣对无瓣为完全显性。在F_2及B_1中,有瓣:无瓣分别为255:1与15:1,表明无花瓣性状的遗传受着核中四对隐性基因p_1p_1p_2p_2p_3p_3p_4p_4的制约。无花瓣基因的育种价值主要体现在减耗节能,包括个体节能(减少建成花瓣的损耗)和群体节能(降低黄色冠层对自然光的吸收与反射损失),以及对菌核病的形态避病能力(田间发病率仅为1.75％)。
Seeds of severval generations of seven crosses between an apetalous line APL-0256 and seven normal cultivars of rapeseed (Brassica napus L.) were sown in the autumn of 1988 and spring of 1989, in order to study the inheritance of the apetalous character. A tetrapetalous iso-genic line of APL-0256 and a high-yielding conventional cultivar Ningyou 7 were used as controls to evaluate the floral morphogenesis, photo-synthetic physiology, disease resistance and breeding potentials of the apetalous trait.
It was found that the apetalous trait is controlled by four pairs of recessive genes. All the F_1 plants in the reciprocal crosses between normal and apetalous parents were petalous, the F_2 generations segregating 255 (petalous) : 1 (apetalous) and the B_1 of the F_1 to the apetalous parent segregating 15 : 1. These observations indicated that the petalous gene (P) is dominant over the apetalous one (p). The genotype of normal tetrapetalous cultivars is P_1P_1P_2P_2P_3P_3P_4P_4, while that of the apetalous line is p_1P_1p_2p_2p_3p_3p_4p_4. As compared with the tetrapetalous cultivars, the apetalous line might have two advantages. One is energy-saving, whether on a single-plant or a population basis. The apetalous rape plants cut down the consumption of dry matter which might otherwise be used for the development of petals. As an apetalous population does not have a non-photosynthetic yollow flower canopy which would otherwise absorb and reflect 59.66% of the total PAR, more light can reach the lower regions within the canopy. This helps keep the lower leaves photosynthetically active for a long time at early flowering stage, and support more effective siliques to develop at the later stage. The other advantage is that the field incidence of Sclerotinia sclerotiorum (Lib.) de Bary can be reduced to 1.75% since flower petals are an important medium for the spread and invasion of the pathogen.
In conclusion, the use of the apetalous mutant of B.napus might open a new way to breeding for high yields, good qualities and disease resistance.
出处
《江苏农业学报》
CSCD
1990年第4期30-36,共7页
Jiangsu Journal of Agricultural Sciences
基金
江苏省科技基金资助项目
关键词
油菜
甘蓝型
无花瓣性状
遗传
育种
Brassica napus L.
Apetalous character
Inheritance
Breeding
