棉花植株顶部棉铃发育过程中物质累积及对温度的响应

【目的】研究7、8果枝棉籽与纤维不同播种条件下物质累计的特点,分析温度变化对籽棉物质分配的影响,以及分期播种后上部果枝棉纤维发育与温度的关系,为机采棉确定播种日期和脱叶剂喷施时间和提高棉纤维品质提供理论依据。【方法】于2017~2018年在新疆乌兰乌苏农业气象试验站开展田间试验,以大田生产播期(4月12日)为对照,两年共设置4个播期,随铃龄变化测定棉籽与纤维物质累积特征、棉花纤维品质等指标。【结果】花后50 d内日均温MDT为23.8℃,≥15℃有效积温为456.8℃的正常播期处理下,新陆早59号、新陆早64号上部果枝单粒棉纤维干物质快速累积期分别在铃龄22~40和18~36 d;MDT下降0.3℃,≥15℃有效积温下降17.5℃的条件下,使新陆早64号单粒棉纤维干物质快速累积期平均累积速率提高且理论最大积累量明显增加;在纤维物质累积过程中,日温差对单粒纤维物质快速累积期长短有着极显著影响;纤维与棉籽间存在异速生长特征,并随着铃期MDT的下降异速生长程度减小;MDT为23.0和20.8℃的晚播条件下早中熟品种新陆中82号的棉籽、纤维发育均表现出了较好的适应性。【结论】棉纤维发育对铃期温度下降较为敏感,在铃龄中后期干物质累积速率的明显降低;纤维与棉籽间的异速生长程度随着铃期MDT的下降而降低;铃期日均温差一定程度上决定了其干物质快速累积期的长短;早中熟品种新陆中82号早熟性较好,适宜在北疆棉区种植。

The Matter Accumulation and Its Response to Temperature during Cotton Fiber Development at the Top of Cotton Plants

【Objective】 To research the characteristics of matter accumulation under different sowing conditions of 7, 8 branch's cottonseed and fiber, analyze the effect of temperature change on the matter distribution of seed cotton and the relationship between cotton fiber development and temperature of upper fruit shoot after sowing by stages in the hope of providing the theoretical basis for determining sowing date and the time of spraying defoliant and improving the quality of cotton fiber. 【Method】Field experiments were carried out at Wulanwusu agricultural meteorological test station between the years 2017 and 2018.The sowing date of field production (April 12) was taken as the control, four sowing dates were set in two years, the accumulation characteristics of cottonseed and fiber and the quality of cotton fiber were measured with boll age. 【Result】 Under the normal sowing date with MDT of 23.8℃ and effective accumulated temperature of 456.8℃ at ≥ 15℃ within 50 days after anthesis, the rapid accumulation periods of dry matter of single grain cotton fiber in the upper fruit branch of Xinluzao 59 and 64 was between 22 - 40 d and 18 - 36 d during the boll stage, respectively. Under the condition that MDT decreased by 0.3℃ and effective accumulated temperature ≥ 15℃ decreased by 17.5℃, the average accumulation rate of dry matter of Xinluzao 64 single grain cotton fiber increased and the theoretical maximum accumulation increased obviously. In the process of fiber matter accumulation, the average temperature difference had a very significant effect on the rapid accumulation period of single fiber material; there was anisotropy between fiber and cottonseed, and the anisotropy decreased with the decrease of boll MDT; MDT was 23.0℃. Under the condition of late sowing at 20.8℃, the fiber development of cottonseed of Xinluzhong 82, an early and medium maturing variety, showed better adaptability. 【Conclusion】Cotton fiber development is more sensitive to temperature drop in boll stage, which is mainly reflected in the significant decrease of dry matter accumulation rate in middle and late boll stage. The allometric growth between fiber and cottonseed decreased with the decrease of boll MDT. The average daily temperature difference in boll period determined the length of rapid accumulation period of dry matter. The early and medium ripening variety Xinluzhong 82 has better precocity and is suitable for planting in the cotton area of northern Xinjiang.