杂交稻新组合再生稻头季及再生季源库特征分析

 以6个两系杂交组合和2个三系杂交组合为材料，比较研究了杂交稻头季与再生季的源库特性和再生稻产量形成的源库关系。结果表明：(1)再生季LAI为头季的1/3左右，再生稻单茎叶面积约为头季稻的1/7~1/3，头季总库容约为再生季的1.5倍，再生稻粒叶比约为头季稻的1.5~2倍；(2)头季稻较大的粒叶比对高产有利；头季稻成熟期LAI较大、粒叶比较小、成熟期单茎鞘干质量较大、茎鞘物质输出率高，有利于再生稻的高产；(3)再生季齐穗期LAI与产量成显著正相关；对高节位再生稻而言，齐穗期单茎叶面积与单茎产量呈极显著正相关，粒叶比与结实率呈负相关、与产量呈极显著负相关。再生稻，特别是高节位再生稻，其源库关系属增源增产型；(4)陆18S/53159、康两优2054、培矮64S/E32和培两优500再生季产量较高，均在5200 kg/hm2以上。综合考虑再生季产量与两季总产，在2002年气候条件下，长沙地区最适于再生栽培的杂交稻是培矮64S/E32，其次是康两优2054和T98A/259。

Source-Sink Characteristics of Main Crop and Ratooning Rice of Several New Hybrid Rice Combinations

Eight hybrid rice combinations were used to study the source-sink characteristics of main crop and ratooning rice in hybrid rice, and the source-sink relationship for yield formation in ratooning rice. The results indicated that:(1) Leaf area index(LAI) of ratooning rice was about one third of that of the main crop, and leaf area per culm of ratooning rice was about from one seventh to one third of that of the main crop. The whole sink volume of the main crop was about 1.5 times of that of ratooning rice. The ratio of grain number to leaf area in ratooning rice was 1.5 to 2 times of that in the main crop. (2) High ratio of grain number to leaf area was beneficial to get high yield in the main crop. High LAI at maturity stage, low ratio of grain number to leaf area, high weight of stem-sheath at maturity stage and high export percentage of the matter in stem-sheath in the main crop were helpful to obtain high yield in ratooning rice. (3)There was a positive correlation at the 0.05 level between LAI at full heading stage and yield of ratooning rice. To upper-node ratooning rice, there were a positive correlation at the 0.01 level between leaf area per culm at full heading stage and yield per culm, a negative correlation between the ratio of grain number to leaf area and seed setting rate, and a negative correlation at the 0.01 level between the ratio of grain number to leaf area and yield. The type of source-sink relationship of ratooning rice, especially of upper-node ratooning rice belonged to the source-limited. (4)The yields of ratooning rice of Lu 18S/53159, Kangliangyou 2054, Pei′ai 64S/E32 and Peiliangyou 500 were all above 5200 kg/hm². Considering synthetically yield of ratooning rice and the total of the two crops, under the climate conditions of 2002 in Changsha region, the optimal combination for ratooning was Pei′ai 64S/E32, followed by Kangliangyou 2054 and T98A/259.