一、田间选种,提纯复壮 (一)为什么要进行田间选种每个谷子品种,都是由许多在遗传性上相对一致的个体组成的。同一个品种中,各个单株适应环境的能力有强有弱,抗灾力、丰产性有大有小。如果任其自然发展,部分抗灾性差、生活力弱的穗就会使品种的生产力降低。同时,由于年年有1-3％的植株自然杂文,打场、贮藏、运输过程中也可能混入其他品种,因此,种植几年后,在一个品种内就会出现高的、矮的,早熟的、晚熟的等不同植株,给田间管理带来困难,使产量不断降低。所以要年年选种,去杂存优,保持种性,提高产量。田间穗选留种,可使株高、生育期和穗型整齐一致,减轻病害,提高生活力,减少枯秸,增加小穗数,一般增产10％左右。 (二)田间选种的标准选留品种时,要注意不同类型品种的搭配,以适应风、旱、涝、病等自然灾害。也要考虑群众生活及 First, the field selection, purification and rejuvenation (a) why the field selection Each variety of millet, are composed of many relatively genetically identical individuals. In the same species, the ability of each individual plant to adapt to the environment is strong and weak, and its resilience and high yield are high and low. If left unnoticed, some of the disastrous and less viable spikes will reduce the productivity of the breed. In the meantime, since 1-3% of plant natural essays are year after year, other varieties may also be mixed in the process of playing field, storage and transportation. Therefore, a few years after planting, there will be high, short, precocious The late maturity of different plants, to the field management difficulties, so that production continued to decline. Therefore, every year to seed selection, to the excellent hybrids, to maintain species, increase production. Spike selection in the field, can make plant height, growth period and panicle neat, reduce disease, improve vitality, reduce stubble, increase the number of spikelets, the general increase of about 10%. (B) field selection of species of the selected varieties, pay attention to different types of collocation, in order to adapt to wind, drought, waterlogging, disease and other natural disasters. We must also consider the life of the people