南疆不同类型海岛棉品种棉铃内同化物积累与分配特性的研究

 以南疆主栽海岛棉品种为材料，分析不同花期铃部器官同化物质积累动态、再度分配及吐絮棉铃的分配率。结果表明：同化物积累随时间呈“S”型曲线，用Logistic方程进行拟合均达到显著水平。同化物积累达最大值所需时间表现为棉纤维＞种子＞铃壳，新海28比优系193提前5～10 d；同化物再度分配随着花期的推移，铃壳率不断增大，子重率、经济系数、子棉/壳重逐渐减小。铃壳对子棉增重的贡献率，新海28大于优系193；棉铃的胚珠数、种子数、结子效率随开花时间的推移逐步增大，新海28单铃子房胚珠数、单铃种子数比优系193略低，而结子效率稍高；新海28具有开花早，铃期短，铃壳率小，结子效率高，铃壳同化物质的再分配对子棉增重的贡献率、子重率、经济系数、子棉与干重的比值均大于优系193，这是其早开花、早结铃、早吐絮及丰产的遗传生理基础。

Carbon Accumulation and Distribution in Bolls of Island Cotton (Gossypium barbadense L.) in Southern Xinjiang

Sugar accumulation and distribution were studied in the bolls of island cotton cultivated in arid area of southern Xinjiang. Dynamic changes were monitored in different parts of bolls at different developing stages. Analysis of the carbon accumulation showed an 'S' type-curve and could be simulated with a Logistic equation. The length of time for all the boll parts to reach their maximum accumulation showed an order as: fiber﹥cotton seed﹥boll shell. Variety Xinhai 28 reached the maximum accumulation 5 to 10 days earlier than variety Youxi 193. With the development of boll, the assimilation in boll shell re distributed its assimilates and the ratio of boll shell to boll became higher. But the ratio of seeds to boll, the economic coefficient, and the ratio of seed cotton to boll shell weight became lower with the maturation of bolls. As for the contribution of boll shell to the weight of seed-cotton, Xinhai 28 showed a larger portion than Youxi 193. The numbers of ovules, seeds and the percentage of seed weight correlated with the blooming time. Bolls of Xinhai 28 were smaller than those of Youxi 193 in terms of ovule and seed numbers per boll. However, its seed fertility was higher than that of Youxi 193. Xinhai 28 has an earlier blooming, a shorter period of boll maturation, a lower ratio of boll to shell, a higher percentage of developed seeds, more contribution to seed-cotton weight in redistributing of its shell assimilates. The boll ratio, the economic coefficient and the ratio of seed cotton to dry weight, are higher in Xinhai 28 than that in Youxi 193. Apparently such features make Xinhai 28 some advantages over Youxi 193 in terms of early flowering, early development of bolls, early boll maturation and high yield.