杂交水稻繁制种隔离距离的研究

Study on Isolated Distance of Seed field for seed reproduction in Hybrid Rice

1986—1987年以不育系做受体,采用盆栽方法于开花前将受体移至粉源东南西北四个方向,每隔25米设一档次,最远距粉源275米,腊熟期统计受体的结实率。根据我们对玉米、高粱种子田隔离的研究,从定量水平求得的有无父本花粉竞争条件下污染结实率差异的统计量得知,无花粉竞争条件下的数值是有花粉竞争的三倍。本试验(无父本花粉竞争)在隔离25米,两年四个方向的平均结实率应为4.44％÷3=1.40％;隔离75米为1.20％÷3=0.40％,纯度分别可达98.52％和99.60％,均已超过国家一级杂交种纯度97％和一级亲本种纯度99.5％的标准。故此,认为国家现行隔离距离丘陵区50米以上,平湖区100米以上应更正为制种田25米以上,亲本繁殖田75米以上。

The sterile line in pot culture was made the pollen acceptor in 1986 - 1987. The pollen acceptors were moved to pollen source field at north,east,south and west four different directions before flowering. The Situations of each pollen acceptor were placed by every alternate 25m, the farest one is apart from pollen source field 275m. The percentage of seed setting was calculated on waxy ripe stage. According to our study on isolation of seed field in corn and sorghum,, the percentage of contamination seed setting in seed field which had no male pollen competition was three times than that of having male pollen competition. The study showed the average percentage of seed setting of no male pollen competition, isolated by 25m at four directions (north, east, south and west) and two years was 4. 44%÷3=1. 48% ( the isolation of 75m was 1. 20÷3 = 0. 40%. The purity of hybrid seed came to 98. 52% and 99. 60% respectively. Each one of which has exceeded purity standard of National First Class Hybrid Seed and purity of parent Seed by 97% and 99. 5% respecfively. According to above mentioned. We consider that isolated distance of national present standard above 50m in hilly land and above 100m in plain lake area should be corrected as above 25m for hybrid seed production field and above 75m for parent seed growing field.