【作者】 张慧；

【导师】 张凯；

【作者基本信息】 新疆农业大学 ， 农业资源与环境， 2023， 硕士

【摘要】 棉花是新疆的主要经济作物,在我国乃至全世界具有重要地位,而干旱是影响新疆棉花生产的主要因素之一,农业用水匮乏和分布不均匀制约着新疆棉花产业的可持续发展,因此通过灌溉调控棉花生长进而提高灌溉水利用效率是目前棉花栽培领域研究的重要内容之一。本研究在新疆阜康市彭家湾村冰湖三队棉花种植区开展了2年田间试验,在膜下滴灌条件下设置不同的灌溉量处理W4(CK;正常灌溉),W3(轻度亏水;正常灌溉的85%),W2(中度亏水;正常灌溉的75%),W1(重度亏水;正常灌溉的60%),测定了棉花株高、果枝数、结铃特征等生长发育指标和产量构成指标,计算了灌溉水利用效率,同时采样后对棉花渗透调节物质和保护酶活性及内源激素含量等生理生化指标进行分析,揭示水分调控影响棉花生长的机理。结果表明:(1)随着灌水量的减少,棉花进入各生育时期的时间提前,且棉花在不同生育期的生长发育和结铃情况基本以灌水量多的处理组效果最好。减少灌溉量提前了棉花的开花、结铃和吐絮的时间,同时也缩短了棉花的整个生长周期。减少灌溉量可以显著降低棉花生物量的积累,棉花的果枝数、主茎节数、果枝台位和总铃数均随着灌溉量的减少逐渐递减。在幼铃期棉花的单株蕾铃数对水分亏缺响应最为明显,中部冠层的坐果数随着灌溉量的降低而减少,且不同处理间存在显著性差异(P<0.05),因此在幼铃期需保持充足灌溉。(2)籽棉产量随着灌水量的减少逐渐降低。单株结铃数和籽棉产量均随着灌水量的减少而减少,且在不同灌溉处理下存在显著性差异(P<0.05);单铃重对籽棉产量影响不大。与棉花单株结铃数相关性最大的是株高、果枝数和棉铃脱落率,可见,减少灌溉处理主要通过影响棉花的株高、果枝数和棉铃脱落率来影响单株结铃数,最终影响籽棉产量。(3)棉花灌溉水利用效率随着灌溉量的减少逐渐升高。在W1(重度亏水)灌溉处理时灌溉水利用效率最高,说明降低灌溉量能够提高棉花的灌溉水利用效率,在既能提高灌溉水利用效率又能保证籽棉产量的措施上,需权衡二者之间的关系。(4)棉花体内的渗透调节物质含量、抗氧化酶活性和内源激素含量均会随着灌溉量的减少在轻度亏水时表现出应激反应,出现显著增高的趋势。减少灌溉量处理下的脯氨酸(Pro)、可溶性蛋白(SP)含量较W4(对照组)处理显著增加(P<0.05),说明二者对水分响应更敏感。丙二醛(MDA)和超氧化物歧化酶(SOD)的积累量均随着灌溉量的减少逐渐升高。过氧化氢酶(CAT)和过氧化物酶(POD)两种酶的活性均随着灌溉量的减少呈现先增多后降低的趋势,在W1(重度亏水)处理下均有明显的下降。植物内源激素的含量基本随着灌溉量的减少均呈现先增长后降低的变化趋势,基本在W3(轻度亏水)处理下含量最高,说明在轻度亏水状态下对水分亏缺比较敏感。生长素(IAA)和N~6-异戊烯基腺嘌呤(IPA)含量随着灌溉量的减少呈现先降低后升高的趋势,异戊烯基腺嘌呤核苷(IPAS)没有明显规律性变化。(5)主成分分析表明,三个主成分累计贡献率达到94.21%;第一主成分贡献率最大为50.23%,主要反映的是内源激素因子,说明降低灌溉量的条件下激素类物质含量变化能较多的反映和影响棉花生长发育情况。结合主成分载荷情况和综合得分情况得出,可溶性蛋白(SP)、茉莉酸(JA)、N~6-异戊烯基腺嘌呤(IPA)、脯氨酸(Pro)、生长素(IAA)等生理生化指标对灌溉量的相应更敏感,可作为判定、影响棉花生长发育的主要生理指标。综上所述,灌溉量处理可能通过调控植物体内可溶性蛋白(SP)、茉莉酸(JA)、N~6-异戊烯基腺嘌呤(IPA)、脯氨酸(Pro)、生长素(IAA)的含量发生变化,进而对棉花的株高、果枝数和棉铃脱落率产生影响,使棉花的单株结铃数发生改变,最终影响籽棉产量。另外,结合棉田灌溉水利用效率和不同生育期需水规律,建议可在水分敏感期(幼铃期)对棉花保证充足灌溉,来提高棉花结铃和坐果率,在蕾期、盛铃期、吐絮期对新疆棉花适度减少灌溉量,提高棉田灌溉水利用效率。在保证有较高棉花产量的同时,节约水资源,实现社会经济和生态环境效益的最优化。更多还原

【Abstract】 Cotton is the main cash crop in Xinjiang and plays an important role in China and even the world.Drought is one of the main factors affecting cotton production in Xinjiang.Lack of agricultural water and uneven distribution restrict the sustainable development of cotton industry in Xinjiang.Therefore,regulating cotton growth through irrigation to improve irrigation water efficiency is currently one of the important research topics in the field of cotton cultivation.This study conducted a 2-year field experiment in the cotton planting area of Binghu Third Brigade,Pengjiawan Village,Fukang City,Xinjiang.Under the condition of drip irrigation under plastic film,different irrigation treatments were set up,including W4(CK;normal irrigation),W3(mild water deficit;85%of normal irrigation),W2(moderate water deficit;75%of normal irrigation),and W1(severe water deficit;60%of normal irrigation).The cotton plant height,number of fruit branches,and The growth and development indicators such as boll setting characteristics and yield composition indicators were calculated for irrigation water efficiency.At the same time,physiological and biochemical indicators such as osmotic regulating substances,protective enzyme activity,and endogenous hormone content of cotton were analyzed after sampling,revealing the mechanism of water regulation affecting cotton growth.The results indicate that:(1)As the amount of irrigation decreases,the time for cotton to enter each growth stage is advanced,and the treatment group with more irrigation has the best effect on the growth,development,and boll setting of cotton at different growth stages.Reducing irrigation has advanced the flowering,boll setting,and boll opening time of cotton,while also shortening the entire growth cycle of cotton.Reducing irrigation can significantly reduce the accumulation of cotton biomass.The number of fruit branches,main stem nodes,fruit branch positions,and total bolls of cotton gradually decrease with the decrease of irrigation.The number of buds and bolls per plant of cotton during the young boll stage has the most significant response to water deficit.The number of fruit sets in the middle canopy decreases with the decrease of irrigation amount,and there is a significant difference between different treatments(P<0.05).Therefore,sufficient irrigation needs to be maintained during the young boll stage.(2)The yield of seed cotton gradually decreases with the decrease of irrigation amount.The number of bolls per plant and seed cotton yield decrease with the decrease of irrigation amount,and there is a significant difference(P<0.05)under different irrigation treatments;The single boll weight has little effect on the yield of seed cotton.The most correlated factors with the number of bolls per plant of cotton are plant height,number of fruit branches,and boll shedding rate.It can be seen that reducing irrigation treatment mainly affects the number of bolls per plant by affecting the plant height,number of fruit branches,and boll shedding rate of cotton,ultimately affecting seed cotton yield.(3)The water use efficiency of cotton irrigation gradually increases with the decrease of irrigation volume.In W1(severe water deficit)irrigation treatment,the irrigation water utilization efficiency is the highest,indicating that reducing irrigation volume can improve the irrigation water utilization efficiency of cotton.In terms of measures that can improve irrigation water utilization efficiency while ensuring seed cotton yield,it is necessary to balance the relationship between the two.(4)The content of osmoregulation substances,antioxidant enzyme activity,and endogenous hormone content in cotton will exhibit a stress response with a decrease in irrigation volume during mild water deficit,showing a significant increase trend.The content of proline(Pro)and soluble protein(SP)under reduced irrigation treatment significantly increased compared to the W4(control group)treatment(P<0.05),indicating that both were more sensitive to water response.The accumulation of malondialdehyde(MDA)and superoxide dismutase(SOD)increased with the decrease of irrigation amount.The activities of catalase(CAT)and peroxidase(POD)showed a trend of first increasing and then decreasing with the decrease of irrigation amount,and both showed a significant decrease under W1(severe water deficit)treatment.The content of endogenous hormones in plants shows a trend of first increasing and then decreasing with the decrease of irrigation amount,with the highest content under W3(mild water deficit)treatment,indicating that they are more sensitive to water deficit under mild water deficit conditions.The contents of auxin and N~6-isopentenyl adenine(IPA)decreased first and then increased with the decrease of irrigation amount,while N~6-isopentenyl adenosine(IPAS)did not change regularly.(5)Principal component analysis shows that the cumulative contribution rate of the three principal components reaches 94.21%;The maximum contribution rate of the first principal component is 50.23%,mainly reflecting endogenous hormone factors,indicating that changes in hormone content under reduced irrigation conditions can more reflect and affect the growth and development of cotton.According to the principal component load and comprehensive score,soluble protein(SP),jasmonic acid(JA),N~6-isopentenyladenine(IPA),proline(Pro),auxin(IAA)and other physiological and biochemical indicators are more sensitive to the corresponding irrigation amount,which can be used as the main physiological indicators to determine and affect the growth and development of cotton.To sum up,irrigation treatment may change the content of soluble protein(SP),Jasmonic acid(JA),N6 isopentenyl Adenine(IPA),proline(Pro),and auxin(IAA)in plants,and then affect the plant height,number of fruit branches,and boll abscission rate of cotton,change the number of bolls per plant of cotton,and ultimately affect the yield of seed cotton.In addition,considering the efficiency of irrigation water use in cotton fields and the water demand patterns at different growth stages,it is recommended to ensure sufficient irrigation for cotton during the water sensitive period(young boll stage)to improve the boll setting and fruit setting rate of cotton.During the bud stage,full boll stage,and boll opening stage,it is recommended to moderately reduce irrigation amount for Xinjiang cotton and improve the irrigation water use efficiency of cotton fields.While ensuring a high cotton yield,it saves water resources and optimizes socio-economic and ecological environmental benefits.更多还原