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为了摸清用于生产玉米种子的种质来源和变化趋势,美国种子贸易协会(ASTA)从1956年至1984年止进行了6次关于育成品系的使用和生产、自交系资源的选育、雄性不育细胞质资源的应用等方面情况的调查。结果表明:1984年生产的杂交种亲本中含有Reid种质的占总产量的88%;属常规细胞质型的占87%。用于生产玉米种子的种质来源,已从过去高度使用国家育成品系逐步转向私人育成品系。一、育成品系使用上的变化用于生产杂交种的国家育成品系从1970年始呈稳步下降的趋势。1984年在85个国家育成的自交系中用于生产杂交种种子的数量超过总需种量的3%的只有1个,而1979年在53个中就有3个;超过
To understand the sources and trends of germplasm used to produce maize seeds, the American Seed Trade Association (ASTA) conducted six uses and production of coffered lines between 1956 and 1984, breeding of inbred lines, Male sterile cytoplasm resources application aspects of the investigation. The results showed that the hybrids produced in 1984 contained 88% of the total yield of Reid germplasm and 87% of the conventional cytoplasm. The sources of germplasm used for the production of maize seeds have shifted from the high use of national caterings to private cows in the past. First, the changes in the use of fertilized strains National breeding products used in the production of hybrid strains from the beginning of 1970 showed a steady downward trend. Only one of the three inbreds bred in 85 countries in 1984 for producing hybrid seeds exceeded 3% of total demand, up from three of 53 in 1979;