每穴苗数对北方不同穗型粳稻物质生产和抗倒伏能力的影响

2012-2013年以少蘖粳Ri22和沈农265为试验材料，研究每穴苗数对物质生产和抗倒伏能力的影响。结果表明，(1)少蘖粳Ri22和沈农265抽穗前和抽穗后干物质生产量及总干物重均随每穴苗数增加而增加，茎鞘和叶片物质转运率和贡献率随每穴苗数的增加而降低；(2)少蘖粳Ri22和沈农265各节间抗折力均表现为每穴2苗>每穴4苗>每穴6苗，各节间倒伏指数均表现为每穴2苗<每穴4苗<每穴6苗，差异均未达到显著水平；(3)少蘖粳Ri22和沈农265有效穗数随每穴苗数增加而显著增多，每穗粒数随每穴苗数增加而显著减少，结实率和千粒重的差异没有达到显著水平；(4)少蘖粳Ri22和沈农265的产量随着每穴苗数的增加而增加，差异未达到显著水平。为了实现高产与抗倒能力的统一，少蘖粳Ri22在沈阳地区种植适宜苗数为每穴2~4苗，而沈农265则可以适当密植。

Effects of Seedlings per Hole on Matter Production Characteristics and Lodging Resistance in Japonica Rice with Different Panicle Types

The effects of planting seedlings per hole on the rice matter production characteristics and lodging resistance were studied using the ideal japonica rice varieties Ri22 and Shennong 265 in 2012–2013. The main results were as follows: (1) Dry matter accumulation and total dry matter accumulation of Ri22 and Shennong265 before or after heading increased with the increasing of seedlings per hole, the transport rate and contribution rate of stem and leaf showed the opposite trend. (2) There was a slight influence on internode bending moment and lodging index of Ri22 and Shennong 265 with different seedlings per hole. Internode bending moment decreased slightly with the increasing of seedlings per hole, the lodging index showed the opposite. (3) With the increasing of seedlings per hole, the effective panicles of Ri22 and Shennong265 increased and the total grains per panicle decreased significantly, while seed setting rate and 1000-grain weight had little changed. (4) The yield of Ri22 and Shennong 265 increased slightly with the increasing of seedlings per hole. In order to achieve the unity of high yield and lodging resistance, the suitable density for Ri22 in Shenyang should be 2–4 seedlings per hole, and more than that density for Shennong 265.