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在株行距15 cm×15 cm(44.4万穴/hm2)、20 cm×20 cm(25万穴/hm2)和30 cm×30 cm(11.1万穴/hm2)3个移栽密度下,研究了移栽密度对双季稻光合特性和产量的影响。结果表明,随密度增加,水稻叶片净光合速率(PN)、实际量子产率(ΦPSⅡ)、表观光合电子传递速率(ETR)和光化学猝灭系数(qP)下降,而非光化学猝灭系数(NPQ)升高。随着叶位的降低,叶片PN下降,密度增加会加剧下层叶片PN的下降。在不同移栽密度下,水稻叶面积指数(LAI)和PN表现互为消长,即随着移栽密度增加,LAI增加,而PN下降。移栽密度对结实率和千粒重影响较小,对有效穗数和每穗总粒数影响较大,移栽密度15 cm×15 cm和20 cm×20 cm的处理间的产量差异较小,但明显高于30 cm×30 cm处理的产量。考虑到人工和秧苗成本,双季稻采用中等移栽密度(20cm×20 cm)较为适宜。
Under three transplanting densities of 15 cm × 15 cm (444,000 hm2), 20 cm × 20 cm (250,000 hl / hm2) and 30 cm × 30 cm (111,000 hm2) Effects of Transplanting Density on Photosynthetic Characteristics and Yield of Double Cropping Rice. The results showed that the net photosynthetic rate (PN), the actual quantum yield (ΦPSⅡ), the photosynthetic electron transport rate (ETR) and the photochemical quenching coefficient (qP) of rice leaves decreased with the increase of the density, while the non-photochemical quenching coefficient NPQ) increased. With the decrease of leaf position, the leaf PN decreased and the density increased, which would exacerbate the drop of PN in the lower leaf. At different transplanting densities, the leaf area index (LAI) and PN performance of rice showed mutual depletion and growth, that is, with the increase of transplanting density, LAI increased and PN decreased. Transplanting density had little effect on seed setting rate and 1000-grain weight, and had a significant effect on effective panicle number and total grain number per panicle. Yield differences between treatments of 15 cm × 15 cm and 20 cm × 20 cm transplanted density were small, Significantly higher than the 30 cm × 30 cm treatment yield. Taking into account the cost of artificial and seedlings, double cropping rice with medium transplanting density (20cm × 20cm) is more suitable.