麦棉两熟周年秸秆还田对棉花产量品质形成的影响及其生理机制

发布时间：2018-01-01 22:31

本文关键词：麦棉两熟周年秸秆还田对棉花产量品质形成的影响及其生理机制　出处：《南京农业大学》2016年博士论文　论文类型：学位论文

【摘要】：转基因抗虫棉迅速推广,其种植面积约占全国棉花种植总面积的70%。转基因抗虫棉载铃多,产量高,但易发生缺钾性早衰,导致棉花低产降质。我国钾矿资源匮乏,需进口大量钾肥。钾肥价贵,农民施化学钾肥积极性不高。作物秸秆含有大量钾素,还田后可以补充土壤钾素。于2011年4月在江苏省南京市(118°50′E,32°02′N)(粘土)和江苏省大丰市(120°28′E, 33°12′N )(砂壤土)进行麦棉两熟制周年秸秆还田定位试验。选用转基因抗虫棉泗杂3号,在棉花季设置小麦秸秆还田,0、4500、9000 kg hm-23个水平(W0、W4500、W9000),在小麦季设置棉花秸秆还田,0、3750、7500 kg hm-2 3个水平(C0、C3750、C7500 ),形成9个周年秸秆还田处理组合。于2012年棉花季增设2个钾肥施用量处理150和300kg K2O hm-2(K150、K300)。本试验从麦棉两熟周年秸秆还田影响棉花产量、品质入手,围绕棉花“叶-铃”系统,揭示秸秆还田下不同棉株、棉铃对位叶、棉纤维钾素水平导致棉花产量品质形成差异的生理机制,为指导麦棉两熟转基因抗虫棉钾肥施用、提高麦棉秸秆利用率提供依据。主要研究结果如下:1全量麦棉秸秆周年还田可基本替代化学钾肥150 kg K2O hm-2麦棉秸秆周年还田和施钾显著提高吐絮期棉花群体叶面积和生物量,提高群体总果节数降低蕾铃脱落率,为棉花搭建高产架子提供物质基础。麦棉秸秆周年还田和施钾显著提高棉花群体光合势(LAD),而净同化率(NAR)显著下降,表明棉花群体光合产物供应能力的提高更多是通过延长群体光合时间而不是提高群体同化能力。麦棉秸秆周年还田和施钾显著提高棉花铃数、铃重和籽棉产量。综合比较基于棉株钾浓度、棉株钾累积量及籽棉产量的秸秆还田对化学钾肥替代率发现,C7500W9000处理(全量小麦秸秆还田9000 kg hm-2 +全量棉花秸秆还田7500 kg hm-2)对150 kg K2O hm-2的替代效果最优,且可使籽棉产量在定位秸秆还田3年内较施钾150 kg K2Ohm-2无显著降低。分析棉花群体生长和产量及产量构成的变异来源可知,当季小麦秸秆还田和施钾显著提高棉花群体生长和产量及产量构成,前茬棉花秸秆还田无显著影响或提高较少。棉花群体生长和产量及产量构成在南京试点(低钾黏土)较大丰试点(高钾砂壤土)更敏感。2麦棉秸秆周年还田提高棉花上部和中部外围果枝产量和纤维品质麦棉秸秆周年还田和施钾显著影响棉花产量、品质在空间上的分布,主要表现于上部果枝和外围果节棉铃。当季小麦秸秆还田和施钾通过显著增加上部及中部外围果枝棉铃铃数、各果枝部位铃重来提高棉花产量。前茬棉花秸秆还田对棉花不同果枝部位铃数、铃重基本无显著影响。当季小麦秸秆还田和施钾显著增加上部及中部外围果枝棉纤维断裂比强度、马克隆值来提高棉纤维品质,对各果枝部位纤维长度影响较小。前茬棉花秸秆还田显著降低上部果枝纤维断裂比强度,对其余果枝部位纤维品质基本无显著影响。综上,从空间分布来看,上部果枝和各层次外围果节产量和棉纤维品质更易受到小麦秸秆周年还田和施钾的正向影响,各果枝部位对棉花秸秆还田基本无响应。从产量构成和纤维品质指标来看,在低钾黏土条件下,铃重较铃数更敏感,马克隆值较断裂比强度更敏感,纤维长度最不敏感。3麦棉秸秆周年还田增加棉铃对位叶光合产物输出和对位铃生物量小麦秸秆周年还田和施钾显著提高中部果枝内围棉铃生物量,而棉花秸秆还田对棉铃生物量无显著影响。小麦秸秆还田和施钾显著提高棉铃对位叶Pn、SPAD值,显著降低蔗糖、可溶性糖、淀粉和非结构性碳水化合物含量,显著提高蔗糖淀粉比,表明棉铃对位叶光合产物倾向以蔗糖形式存在,更有利于光合产物输出。棉花秸秆还田对棉铃对位叶光合性能和碳水化合物含量无显著影响。小麦秸秆周年还田和施钾显著提高棉铃对位叶氮浓度,而棉花秸秆还田无显著影响。棉铃对位叶C/N与棉铃生物量显著负相关。在本试验条件下,碳氮代谢相关酶活性并不能很好解释光合产物含量在棉铃对位叶的变化。综上,小麦秸秆还田和施钾较棉花秸秆还田增加棉铃对位叶光合产物输出,较低的棉铃对位叶C/N有利于棉铃生物量的提高。4麦棉秸秆周年还田下通过提高棉纤维蔗糖转化成纤维素的效率,促进纤维生物量累积和纤维品质形成小麦秸秆还田和施钾显著提高中部果枝内围铃棉纤维生物量,棉花秸秆还田对其影响不显著。在2012年小麦秸秆还田显著提高棉纤维长度、马克隆值,施钾显著增加纤维长度,棉花秸秆还田无显著影响;2013年小麦秸秆还田和施钾显著提高纤维品质,棉花秸秆还田显著提高纤维断裂比强度和马克隆值,却降低了纤维长度。通过对棉纤维品质形成过程的拟合并观察品质形成特征值可知,纤维长度:2012年小麦秸秆还田和施钾提高纤维最大伸长速率,2013年小麦秸秆还田提高纤维最大伸长速率,施钾提前快速伸长起始期延长快速伸长期;断裂比强度和马克隆值:小麦秸秆还田和施钾较棉花秸秆还田快速增加速率快,快速增加起始期早,快速增加持续期长。小麦秸秆还田下棉纤维蔗糖含量显著低于施钾和棉花秸秆还田,而纤维素含量则在小麦秸秆还田和施钾下显著提高,表明小麦秸秆还田和施钾条件下棉纤维蔗糖转化纤维素效率高,且施钾较小麦秸秆还田处理下纤维细胞中纤维素合成底物蔗糖更富余。在本试验条件下,蔗糖代谢相关酶活性并不能很好解释蔗糖含量在棉纤维细胞中的变化。棉纤维生物量和纤维长度与棉铃对位叶钾浓度显著正相关,在2013年纤维生物量和断裂比强度与棉铃对位叶C/N呈显著负相关,表明棉铃对位叶中钾浓度较高和C/N较低有利于纤维生物量的累积和品质的优化。因此,在不同土壤类型的两试点,基于棉花籽棉产量,麦棉秸秆周年还田实现了对化学钾肥的替代或部分替代,通过延长棉花群体光合时间,为棉花高产打下基础。另外,麦棉秸秆周年还田通过提高棉花上部和中部外围果枝产量和纤维品质进而提高产量、品质。
[Abstract]:Transgenic cotton spread rapidly, its planting area accounts for the national total area of cotton 70%. transgenic cotton boll load, high yield, but prone to potassium deficiency leads to premature senescence, cotton yield degradation. China's potash resources shortage, need to import large amounts of potash fertilizer. Potash fertilizer price, farmers use chemical fertilizer enthusiasm not high. Crop straw contains large amounts of potassium, soil can replenish the soil potassium. On April 2011 in Jiangsu city of Nanjing province (118 degrees 32 degrees 50 'E, 02' N) (clay) and Jiangsu Dafeng (120 degrees 33 degrees 28 'E, 12' N) (Sha Rangtu) of Wheat the two anniversary of the straw Cotton Cropping system experiment. The transgenic cotton Siza 3 wheat straw, set in the cotton season, 045009000 kg hm-23 (W0, W4500, W9000 level), cotton straw returning in the wheat season, 037507500 kg hm-2 3 level (C0, C3750, C7500), 9 anniversary of straw Combined treatment in 2012. Cotton Season 2 additional K 150 and 300kg K2O hm-2 (K150, K300). The test from two crops of wheat and cotton straw returning anniversary of cotton yield, quality of cotton leaves around - ring "system, revealing the straw under different cotton, leaf subtending cotton fiber. Potassium level leads to the formation of the physiological mechanism of cotton yield and quality difference, for K cooked two transgenic cotton wheat cotton guide application, improve the rate of use on the basis of cotton and wheat straw. The main results are as follows: 1 of the total amount of cotton and wheat straw returning can basically replace chemical fertilizer of 150 kg K2O hm-2 of cotton and wheat straw returning and K anniversary significantly increased the leaf area and biomass of cotton boll increased the total fruit abscission rate to reduce the node number, and provide the material basis for cotton yield of cotton and wheat straw. The shelf build anniversary and potassium significantly improved returning cotton group Body photosynthetic potential (LAD), and net assimilation rate (NAR) decreased significantly, that of photosynthetic products cotton supply capability is more extended through photosynthesis time rather than improve assimilation ability. Cotton and wheat straw returning and potassium significantly increased the annual cotton boll number, boll weight and seed yield. Based on the comparison of cotton potassium concentration, potassium accumulation of cotton and cotton yield of straw chemical potassium replacement rate, C7500W9000 (total amount of wheat straw was 9000 kg hm-2 + total amount of cotton straw was 7500 kg hm-2 150 kg K2O hm-2) to replace the optimal effect, and can make the seed cotton yield in straw positioning 3 years is k 150 kg K2Ohm-2 decreased significantly. Analysis of sources of variation of cotton population growth and yield and yield components of wheat straw and season, when k significantly increased cotton population growth and yield and yield components, the No significant effect of cotton straw stubble or less. Population growth and improve cotton yield and yield components in Nanjing pilot (low potassium clay) is the pilot (Dafeng high potassium sand loam) are more sensitive to.2 cotton and wheat straw incorporation improved the cotton anniversary of upper and middle peripheral fruit yield and fiber quality of cotton and wheat straw returning and K anniversary significant effects of cotton yield and quality distribution in space, mainly in the periphery of the upper branches and fruit Festival. When cotton season wheat straw and potassium significantly increased through the upper part and the middle part of peripheral branches of boll number, boll weight of the fruiting branches increase cotton yield. The stubble cotton straw on different cotton fruiting bolls basically, boll weight had no significant effect. When the season of wheat straw and potassium significantly increased the upper part and the middle part of peripheral branches of cotton fiber breaking strength, micronaire value to improve the quality of cotton fiber, the fruit Branch site fiber length had little effect. The stubble cotton straw was significantly lower than the upper branches of fiber fracture strength, basically had no significant effect on the rest of the fruiting fiber quality. Therefore, judging from the spatial distribution, positive effect on upper branches and levels of peripheral fruit yield and quality of cotton fiber section are more susceptible to wheat straw returning and K anniversary the different fruiting branches of cotton straw no response. From the yield and fiber quality indicators, clay in low potassium condition, boll weight is more sensitive to the boll number, micronaire value is more sensitive than the fracture strength, the fiber length is not sensitive to.3 cotton and wheat straw returning increased annual subtending leaf photosynthesis the product output and biomass of wheat straw returning and on the anniversary of potassium increased significantly in the middle branch of bolls of cotton straw biomass, but had no significant effect on boll biomass of wheat straw. SPAD straw and potassium significantly increased leaf subtending Pn value decreased significantly, sucrose, soluble sugar, starch and non structural carbohydrate content increased significantly than that of sucrose and starch, subtending leaf photosynthetic products tend to exist in the form of sucrose, more conducive to photosynthetic product output. Cotton straw on the subtending leaf light the photosynthesis and carbohydrate content had no significant effect. Wheat straw returning anniversary and potassium significantly increased nitrogen concentration, while cotton straw had no significant effect. C/N and boll subtending leaf biomass was significantly negatively correlated. In this experiment, the carbon and nitrogen metabolism related enzyme activity and can't explain the change of light photosynthate content in the leaves subtending. To sum up, wheat straw and potassium than cotton straw could increase the subtending leaf photosynthetic product output, lower in leaf subtending cotton C/N. The biomass of cotton and wheat straw returning increased.4 anniversary by increasing the efficiency of cotton fiber cellulose into sugar, promote the formation of wheat straw fiber and fiber quality and biomass accumulation of potassium significantly increased the middle branch inside boll cotton biomass, cotton straw has no significant effect on it. Improve cotton fiber length in 2012, wheat straw, micronaire value, potassium significantly increased the fiber length, no significant effect of cotton straw; 2013 wheat straw and potassium significantly improve the fiber quality of cotton straw significantly increased the fiber breaking strength and micronaire, fiber length is decreased. By forming a fitting observation quality formation characteristics the results showed, the fiber length of cotton fiber quality: 2012 wheat straw and potassium increased maximum fiber elongation rate, improve the wheat straw returning in 2013 The maximum fiber elongation rate, K in advance of the rapid elongation period initial rapid elongation period; breaking strength and micronaire value: wheat straw and Cotton Straw Potassium is rapid increasing rate, rapid increase in initial stage of early, rapid increase in long duration. Cotton fiber sucrose content was significantly lower than that of wheat straw under potassium and cotton straw, while the cellulose content in wheat straw and potassium significantly increased, the results showed that the wheat straw and potassium under the condition of cotton fiber sucrose conversion of cellulose with high efficiency, and potassium than wheat straw processing cellulose fiber cell synthesis of sucrose more surplus. Under the conditions of this experiment, the change of sucrose metabolism related enzyme activity and could not explain the sucrose content in cotton fiber cells. Positive correlation of cotton fiber and fiber length and biomass of the subtending leaf potassium concentration in 2013. Annual biomass and fiber breaking strength was negatively correlated with leaf subtending C/N, showed that the higher concentration of C/N and subtending Ye Zhongjia low is propitious to optimize the biomass and accumulation of fiber quality. Therefore, in different soil types of the two pilot, based on cotton yield, cotton and wheat straw returning to achieve chemical anniversary K or partly replace, by extending the cotton canopy photosynthetic time for cotton yield basis. In addition, cotton and wheat straw returning by improving the anniversary of upper and middle peripheral branches of cotton yield and fiber quality and yield and quality.

【学位授予单位】：南京农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S562;S141.4

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