不同咸水利用方式对棉花叶绿素荧光参数及土壤盐分的影响

【目的】本研究旨在科学合理地利用浅层咸水资源。【方法】依托短期定位试验开展了在第3年和第4年不同咸水利用方式下(CK:造墒和蕾期灌淡水;T1:造墒和蕾期灌咸淡混配矿化度3 g·L~(-1)的微咸水;T2:淡水造墒蕾期灌矿化度5 g·L~(-1)咸水;T3:造墒和蕾期灌矿化度5 g·L~(-1)咸水;T4:淡水造墒蕾期不灌水)棉花长势、叶绿素荧光参数、土壤盐分累积及其运移的变化。【结果】T1和T2处理的齐苗率、株高、干物质质量、叶面积指数、叶绿素荧光参数、产量及霜前花率与CK无显著差异,土壤盐分含量较CK有所增加,但未对棉花生长产生明显抑制。T3处理的棉花长势指标、叶绿素荧光参数较CK显著降低,0～100 cm土壤盐分含量较CK明显增加。【结论】从土壤质量安全和咸水高效利用的角度考虑,连续4年用3 g·L~(-1)的咸淡混合水灌溉或用淡水与5 g·L~(-1)的咸水轮灌不仅能节约淡水,且不影响棉花产量。本研究结果为当地在棉花生产中安全利用咸水提供技术参考。     

咸淡水轮灌对滨海盐碱地设施番茄产量及品质的影响

在滨海盐碱地以设施番茄为研究对象,设置4种咸水淡水轮灌次数处理：1:1 (T1)、2:1 (T2)、3:1 (T3)、4:1 (T4),以淡水灌溉为对照,探究不同灌溉模式对番茄生长,产量及品质的影响,为盐碱地设施番茄咸水灌溉制度提供数据支撑。结果表明：在咸淡水轮灌处理下,番茄的生物量随着咸水灌溉次数的增加呈先升高再降低的趋势,T1、T2处理下植株生物量积累明显,与对照达到显著水平;随着咸水灌溉次数的增加,T1、T2处理产量及单果重较对照无明显变化,其他处理番茄产量、单果重显著降低;从果实品质分析,各处理均不同程度提高了果实品质。综合分析,T1、T2处理在一定程度上保证了番茄正常生长及产量稳定,并提高了果实品质,是滨海盐碱地区合理有效的咸淡水轮灌模式。     

咸水膜下滴灌对棉花生长和产量的影响

试验研究了膜下滴灌方式下持续利用咸水灌溉对棉花生长和产量的影响。试验设置了3种灌溉水盐度水平:0·33(淡水)、3·62和6·71dS/m。结果表明:土壤盐分则表现出了不同程度的表聚。不同灌溉水盐度处理棉花的干物质积累无明显差异。咸水灌溉后,棉花的产量随着灌溉水盐度的增加有所降低,但差异不显著。说明棉花具有一定的耐盐性,少量咸水灌溉对棉花生长和产量的影响不明显。     

微咸水对滴灌棉花冠层光合特征及产量品质的影响

为探讨微咸水对新疆膜下滴灌棉花影响效果,利用排碱渠微咸水与河水混合方式,以河水为对照(CK),设置3 g/L和5 g/L两个微咸水矿化度,研究微咸水对滴灌棉花冠层光合特征及产量品质的影响。结果表明:灌溉初期微咸水对棉花影响不明显,至盛花期影响逐渐增强,与对照相比,微咸水滴灌使棉花LAI、MTA、Pn均降低,且5 g/L降幅大于3 g/L,而3 g/L蒸腾速率和气孔导度高于CK和5 g/L。微咸水滴灌使棉花产量降低,3 g/L下降不明显,5 g/L则显著下降,主要原因是单株铃数显著下降,而单铃重呈增加趋势,衣分无明显变化。微咸水对纤维长度和比强度无显著影响,但马克隆值显著增大。因此,低矿化度的微咸水在新疆棉花生产中可适当使用,是缓解棉花旱情实现稳产高产的重要途径。     

咸-淡水交替漫灌淋洗改良滨海盐土效果

为探讨咸-淡水交替淋洗改良滨海盐土效果和节水潜力,通过土柱模拟试验,对咸-淡水交替淋洗下土壤溶液电导率变化、淋出液矿化度变化、淋洗用水量等进行了研究。结果表明,咸-淡水交替淋洗模式咸水(矿化度5.35 g L_-1)淋洗阶段,当100 cm深土体底部开始有淋出液时,距土表40 cm深处土壤溶液电导率下降已非常明显,而距土表80 cm、100 cm深处土壤由于盐分的聚积而电导率较高；咸水持续淋洗下40 cm深处土壤电导率始终缓慢下降,而80 cm、100 cm深处土壤电导率变化历经较快、快速、缓慢下降三个过程。咸-淡水交替淋洗模式淡水淋洗阶段,前期不同深度处土壤溶液电导率基本保持稳定；随着淋洗水量的增加,由土表向下不同深度位置土壤溶液电导率先后经过快速下降和缓慢下降两个过程。咸-淡水交替淋洗模式咸水淋洗阶段,淋出液矿化度变化经过快速、较快、缓慢下降三个过程,直至下降到7.32 g L_-1。淡水替换咸水继续淋洗下,前期淋出液矿化度保持稳定,当淡水淋洗水量增加到7 L(27.49 cm水层)时淋出液矿化度开始下降。咸-淡水交替淋洗模式咸水、淡水淋洗阶段结束后100 cm深土体土壤平均含盐量从初始的23.92 g Kg_-1下降到5.92 g Kg_-1和1.46 g Kg_-1,咸、淡水淋洗水量分别为21.45 L和14.85 L,与对照淡水淋洗模式比较咸-淡水交替淋洗模式淡水节约率为25.38%。咸-淡水交替淋洗模式改良滨海盐土效果较好,且节水潜力较高,但相应需要更长的淋洗改良时间。     

不同矿化度咸水灌溉对小麦生长及产量的影响研究

为了研究小麦对不同矿化度咸水灌溉的综合反应,于2007-2008和2008-2009年度在河北省农林科学院旱作农业研究所试验站,分别采用1(CK),2,4,6,8 g/L 5个矿化度咸水对石家庄8号、衡观35、山融3号、衡观136和沧6004 5个小麦品种进行灌溉研究。结果表明,小麦的株高、生物量、叶面积和群体随灌溉水矿化度增高而降低;比叶重(叶片厚度)、叶绿素含量以及千粒重随灌溉水矿化度增高而呈现升高趋势。这一研究结果表明,可以利用适度的咸水一定程度上塑造合适的株型。灌溉水的盐分对小麦群体的影响是造成产量降低的重要原因,采用具有一定株高和分蘖成穗率强的小麦品种,适当加大播量是提高咸水灌溉小麦产量的重要手段。     

微咸水淋洗重壤质滨海盐土的盐分变化研究

为了节约淡水资源,合理开发利用微咸水代替淡水来改良盐碱地土壤,本研究采用野外小区试验的方法,对不同灌水条件下滨海盐土土壤的脱盐效果进行分析。结果表明,在良好的排水条件下,采用矿化度约3.5 g/L的微咸水淋洗滨海盐土,能使土壤迅速脱盐,脱盐效果明显。综合节水和脱盐效果双重考虑,微咸水淋洗重壤质滨海盐土,以淋洗量1200 m3/hm2,连续淋洗3次为适宜的淋洗方式,能使0~60 cm土壤剖面的全盐量降低到3 g/kg以下,脱盐率达60%以上,土壤盐分含量达到一般绿化植物的生长要求。     

不同残膜量对棉田土壤水盐运移的影响

【目的】为探讨滴灌条件下地膜残留量对棉田土壤水盐时空分布的影响。【方法】本试验在绿洲棉田设0 kg·hm~(-2)、225 kg·hm~(-2)、450 kg·hm~(-2)三种残膜量处理,于棉花播种前、收获后及盛铃期灌水后第1天、第3天、第5天,采用土钻法分层取0～40 cm的土壤,进行土壤盐分测定并比较分析不同处理间差异。【结果】结果表明,残膜降低了膜下滴灌棉田土壤水分的均匀性,同时也导致棉田土壤盐分灌水后在各土层分布不均,灌水后第1天、第3天、第5天, 0 kg·hm~(-2)残膜量处理随着时间推移土壤盐分在各个土层减少,而225 kg·hm~(-2)、450 kg·hm~(-2)处理随着时间的变化各土层在灌水后第1天到灌水后第3天土壤盐分减少,但第5天的土壤盐分大于第3天,两个处理之间无显著差异。从灌水后第1天、第3天、第5天土壤盐分分布可看出,0 kg·hm~(-2)残膜量处理均匀性最好,其次是450 kg·hm~(-2)处理,最后为225 kg·hm~(-2)处理。在棉花种植播种前、收获后,不同残膜量对土壤盐分平衡的影响为:250 kg·hm~(-2)450 kg·hm~(-2)0 kg·hm~(-2);在运移速度上,随着深度和残膜量的增加,耕作层的土壤更容易出现土壤盐分的富集现象。【结论】由此可以说明,残膜的存在会阻碍土壤盐分的向下运移,同时随着残膜量的增加,阻碍土壤盐分的运移程度不同,导致土壤盐分在地表富集。     

不同灌水方式淋洗下滨海盐土的水盐运移特征

为了合理有效地利用水资源,快速改良滨海盐土,通过室内土柱试验探讨了不同灌水方式淋洗下滨海盐土的水盐运移特征。结果表明：咸水的入渗速率要明显高于咸淡交替和淡水入渗。在灌水淋洗后,土壤盐分含量均大幅下降,以先用咸水再用淡水灌水淋洗方式脱盐效果最好,脱盐速度最快,淡水淋洗方式脱盐速度最慢。脱盐后,3个处理土壤的pH值均上升,淡水淋洗土壤pH上升幅度最大,先咸后淡灌水淋洗土壤pH上升幅度最小。采用先咸后淡灌水方式淋洗滨海盐土的综合效果最好,为淡水资源短缺,咸水资源丰富的盐碱地区的盐土淋盐改良提供了科学的方法。     

基于叶绿素荧光参数的滴灌棉花氮素营养估测模型

【目的】建立基于叶绿素荧光参数的棉花叶片氮素营养监测模型,为棉花高效施氮及植株生长状况的无损监测提供方法。【方法】在水肥一体化滴灌条件下,以新陆早58号为试验材料,设置4个施氮水平,测定了棉花生长关键时期顶2(从顶部数起)至顶5叶的叶绿素荧光参数和氮素含量,分析了棉花叶片氮素含量与荧光参数的关系。【结果】(1)棉花出苗70 d后,叶片氮素含量以及光系统II(PSII)潜在光化学活性(Fv/F0)、PSII潜在最大光化学效率(Fv/Fm)、PSII实际光化学效率(ΦPSII)、PSII最大光化学效率(Fv'/Fm')均随着棉花生长呈逐渐下降趋势。(2)不同氮素处理下,各叶片氮素含量以及叶绿素荧光参数Fv/F0、Fv/Fm、ΦPSII和Fv'/Fm'均随施氮量的增加而上升,其中N2 (240 kg·hm-2)处理下各荧光参数值最大。(3)叶片氮含量与Fv、Fv/F0、Fv/Fm、ΦPSII都呈现极显著正相关关系,与荧光参数ΦPSII、Fv'/Fm'间呈现较好的指数函数关系,与荧光参数Fv、Fv/Fm、Fv/F0呈现良好的线性函数关系。顶5叶可变荧光(Fv)与叶片氮素含量建立的关系模型(y=0.0022x+1.6243)的模拟效果最好,决定系数达到0.928,相关系数达到0.963,呈极显著正相关。【结论】适量施氮(240 kg·hm-2)能够提高PSII的活性及PSII反应中心开放部分的比例,进而改善棉花叶片光合能力。顶5叶氮素含量与叶绿素荧光参数Fv构建的模型精确度和拟合效果较其他荧光参数好,因此可以选用荧光参数Fv来监测棉花叶片氮素含量,进而监测植株的氮素营养状况。     

Effects of Exogenous 24-epibrassinolide on Photosynthetic Physiology of CottonSeedlings under Low Temperature

[Objective] The objective of this study was to investigate the effects of exogenous 24-epibrassinolide (EBR) on the photosynthetic physiology of cotton seedlings under low temperature and to provide basis for improving the cold tolerance of cotton by using EBR as growth regulator. [Method] Taking CCRI 60, Lumianyan 28 and Simian 3 as materials, a field experiment was carried out in Institute of Cotton Research of CAAS(Anyang county, Henan province). Before the first low temperature treatment, the cotton seedlings were sprayed with distilled water (Control) and different concentrations of EBR (0.1 mg·L^－1 and 0.2 mg·L^－1), respectively. After 3 days, the relative electrical conductivity, chlorophyll content, rapid chlorophyll fluorescence induction kinetic curve (OJIP) and fluorescence parameters were measured. [Result] Under low temperature, the relative conductivity of CCRI 60, Lumianyan 28 and Simian 3 spraying with EBR decreased by 17.7%～32.8% compared with control, and there was no significant difference between CCRI 60 and Lumianyan 28 in different concentrations of EBR treatments, butthe relative conductivity of Simian 3 treating with 0.2 mg·L^－1 EBR was significantly lower than those treatments with 0.1 mg·L^－1 EBR . The chl a and chl b contents increased by 9.7%～32.6% and 15.0%～18.9%, respectively. The maximum photochemical efficiency of photosystemⅡ (F_v/F_M) and photosynthetic performance index on absorption basis(PI_ABS) increased significantly. PI_ABS of CCRI 60 increase the maximum by 75.6% using 0.1 mg·L^－1 EBR. Lumianyan 28 and Simian 3 increased the maximum by 101.1% and 265.6% using 0.2 mg·L^－1 EBR, respectively; Absorbed photon flux per cross section (ABS/CSm), electron transport flux (further than QA) per active reactive center (ETo/RC) and probability for electron transport (φEo) are significantly increased. [Conclusion] Exogenous EBR can enhance the ability of low temperature tolerance of cotton seedlings and alleviate the inhibition of photosynthesis in cotton at low temperature. The study showed that 0.1 mg·L^－1 EBR performs well in CCRI 60 and 0.2 mg·L^－1 in Lumianyan 28 and Simian 3.     

Effects of Melatonin on the Antioxidant Enzyme Activities and Seed Germination of Cotton (Gossypium hirsutum L.) under Salt-Stress Conditions

[Objective] Cotton (Gossypium hirsutum L.) seed germination, in which melatonin plays an important regulatory role, is seriously affected by soil salinization. Cotton seed germination, antioxidant enzyme activity levels and other physiological indicators were analyzed to clarify the regulatory effects of exogenous melatonin on cotton seed germination under salt-stress conditions. [Method] The experiment was conducted in a greenhouse of Hebei Agricultural University in Baoding City, Hebei Province from 2018 to 2019 using Guoxin Cotton 9 as the material. The germination rate, germination potential, seed biomass after germination, superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities, as well as the malondialdehyde (MDA) content, of cotton seeds were measured after exposure to different melatonin concentrations (0, 10, 20, 50 and 100 μmol·L^－1) and 150 mmol·L^－1 NaCl treatments. [Result] After germination, the germination rate, germination potential, radical length and seed biomass significantly decreased, as did the SOD, POD and CAT activities. However, the MDA content significantly increased under salt-stress conditions. Low exogenous melatonin concentrations (10 and 20 μmol·L^－1) increased the germination potential, germination rate and biomass of cotton seeds, and promoted the elongation of radicals; however high melatonin concentrations (50 and 100 μmol·L^－1) inhibited cotton seed germination and decreased seed biomass after germination. Low melatonin concentrations (10 and 20 μmol·L^－1) increased the SOD, POD and CAT activities and decreased the MDA content in cotton seeds. [Conclusion] Low melatonin concentrations could promote germination and improve the salt tolerance of cotton seeds, while high melatonin concentrations could inhibit their germination. A 20 μmol·L^－1 melatonin concentration is appropriate for regulating cotton seed germination under salt-stress conditions.     

Applying Plant Growth Regulators at Early Stages Affects Maturation of Cotton

[Objective] Early initiation and early maturity are the foundation of high yield and good quality of cotton. The purpose of this study is to determine the effects of plant growth regulators applied at the seedling and squaring stage on the early initiation of flower bud and the rate of the opened cotton boll (ROCB) during later development period, and to provide practical measures for hastening the maturity of cotton. [Method] Several plant growth regulators were applied from cotyledonary to squaring stage under greenhouse and field conditions, water was used as the control. The first fruiting branch node (indicating the initiation of flower bud), the number of bud prior to blooming and the ROCB at mid-term of boll maturation period (23 September, 2017) were compared among treatments. [Result] Under greenhouse conditions, gibberellic acid (GA₃) applied at the cotyledonary stage with 140 μmol·L^－1 as well as the three consecutive applications of sodium nitrophenolate (CSN, 2.23 μmol·L^－1) at the cotyledonary, two-leaf and four-leaf stage made the first fruiting branch node move down by about 0.9 nodes. In field experiments, the application of gibberellin₄₊₇(GA₄₊₇, 288 and 576 μmol·L^－1) at the cotyledonary stage significantly decreased the first fruiting branch node by about 0.4 nodes. Also, the application of 6-benzylaminopurine (6-BA, 44.4 μmol·L^－1) at the three-leaf stage significantly decreased the first fruiting branch node by 0.2 nodes. However, there was no significant correlation between the first fruiting branch node and the ROCB in late September. Moreover, the application of Brassinolide (BR, 0.10 μmol·L^－1) at the bud stage increased the ROCB in late September, which was mainly associated with the increased boll set in the lower and middle fruiting branches. [Conclusion] The reasonable distribution of bolls (concentrated in the lower and middle fruiting branches as well as inner fruiting sites) is more important for the earliness of cotton than lowering the first fruiting branch node.     

防治烟蓟马的生物源农药筛选及其对解毒酶活性影响

【目的】筛选防治烟蓟马(Thrips tabaci Lindeman)的高效生物源农药,探究其对烟蓟马3种主要解毒酶细胞色素P450单加氧酶(Cytochrome P450 monooxygenase,P450)、谷胱甘肽S-转移酶(Glutathione S-transferase,GST)和羧酸酯酶(Carboxylesterase,CarE)活性的影响。【方法】以棉田采集并室内稳定饲养的烟蓟马为供试虫源,用浸叶法测定7种生物源农药对烟蓟马若虫的毒力,选择活性好的3种药剂开展田间药效试验,并在这3种生物源农药亚致死浓度(LC25)剂量处理后测定烟蓟马体内3种主要解毒酶活性。【结果】(1)7种生物源农药对烟蓟马的毒力从高到低依次为乙基多杀菌素、多杀霉素、苦参碱、印楝素、除虫菊素、鱼藤酮、藜芦碱。乙基多杀菌素、多杀霉素和苦参碱对烟蓟马的致死中浓度(LC50)分别为0.011 mg·L^-1、0.274 mg·L^-1、1.479 mg·L^-1。(2)田间药效试验发现,每666.7 m2用2 g、4 g、6 g的60 g·L^-1乙基多杀菌素悬浮剂和10 g的5%(质量分数,下同)多杀霉素悬浮剂处理,施药后7 d防治效果均在90%以上,优于1.3%苦参碱水剂和对照药剂30%噻虫嗪悬浮剂各剂量的防效。(3)LC25剂量处理烟蓟马48 h后,乙基多杀菌素处理的烟蓟马体内P450、GST和CarE活性升高,苦参碱和多杀霉素处理后CarE活性升高,噻虫嗪处理后P450和CarE活性升高。【结论】乙基多杀菌素、多杀霉素和苦参碱对烟蓟马的毒力较高,可用于防控棉田烟蓟马;CarE可能参与了烟蓟马对多杀霉素和苦参碱的解毒代谢,3种主要解毒酶可能均参与了烟蓟马对乙基多杀菌素的解毒代谢。     

脱落酸对棉花体细胞胚胎发生的影响

【目的】研究脱落酸(Abscisic acid, ABA)对棉花体细胞胚胎发生过程中下胚轴脱分化和再分化的影响,优化体细胞胚胎发生体系和初步解析脱落酸调控棉花体细胞胚胎发生分子机制。【方法】以棉花品种中棉所24(CCRI 24)下胚轴为外植体,设置5个ABA浓度0、0.02、0.04、0.06、0.08μmol·L^-1,分别以A0、A1、A2、A3、A4表示,添加至MSB(MS培养基+B5维生素)培养基诱导愈伤和胚性愈伤,研究ABA对棉花下胚轴初始细胞脱分化、愈伤组织诱导和胚性愈伤组织诱导的影响。【结果】ABA促进下胚轴初始细胞脱分化;显著提高愈伤组织的脱分化率和增殖率;0.02μmol·L^-1ABA显著提高胚性愈伤分化率,0.04~0.08μmol·L^-1ABA显著降低胚性愈伤分化率。ABA处理后胚性愈伤和非胚性愈伤的增殖率均显著提高且质地受到影响。0.02~0.08μmol ABA处理下,LBD和LBD在愈伤起始期上调表达。0.02μmol·L^-1ABA处理下,在愈伤增殖早期和中期BBM、LEC1和AGL15上调表达,愈伤增殖后期FUS3、LEA、ABI3基因上调表达。【结论】脱落酸调控的棉花体细胞胚胎发生与相关标记基因的时空性表达密切相关,这些基因表达水平的增加是ABA调控愈伤和胚性愈伤分化的分子基础。     

Effects of Exogenous Proline on the Growth,Physiological Characteristics,and Proline Metabolism of Cotton Seedlings under Boron Deficiency Stress

[Objective] This study investigates the effects of exogenous proline on the growth, physiological responses, and proline metabolism of cotton (Ekang No.8) seedlings treated with varying boron (B) concentrations. [Method] We conducted a randomized experiment with six treatments using the hydroponic method in a greenhouse at Huazhong Agricultural University. We applied three different concentrations of boron, including 0.02 μmol·L^－1 (low-concentration B), 2.5 μmol·L^－1 (medium-concentration B), and 100 μmol·L^－1 (sufficient-concentration B). The first two are boron-deficient treatments. We also applied an exogenous proline treatment at 20 μmol·L^－1(0 μmol·L^－1 as control). When any significant difference among the treatments were observed, the related indicator was measured. [Result] The results showed that exogenous proline inhibited the growth of cotton seedlings under sufficient-concentration B treatment while promoting the absorption of B by roots under low-concentration B treatment. The application of exogenous proline to the seedlings under low-concentration B treatment reduced the contents of proline and H₂O₂ in leaves but increased the accumulation of MDA and H₂O₂ in roots. The activities of SOD and antioxidant enzymes (APX) in the roots and leaves were dramatically enhanced. Conversely, POD activity reduced significantly and there was no significant change in CAT activity relative to low-concentration B treatment. More importantly, we found that the application of exogenous proline under B deficiency increased the activities of P5CS, P5CR, OAT (synthetase), and PRODH (degrading enzyme) in proline metabolic pathways. [Conclusion] Applying exogenous proline under sufficient-B concentration inhibits growth. The application of proline to seedlings under low-B concentration promotes the absorption of B by roots, increases the activity of APX, and decreases the membrane lipid peroxidation in leaves. A B deficiency leads to proline accumulation in plants. The addition of proline under low-B concentration can reduce the proline content in leaves, which is caused by affecting the critical synthetase and catabolic enzyme activities in the proline metabolism pathway (Glu and Orn pathway). The main reason for this occurrence is the significant increase of proline dehydrogenase (PRODH) activity.     

A Regeneration System for Cotton Variety Xinluzao 45 via Somatic Embryogenesis

[Objective] The purpose of this study was to expand upland cotton genotypes suitable for regeneration via somatic embryogenesis, so as to provide excellent receptor materials for the genetic transformation of cotton. [Method] Six different hormone combinations were studied to establish a somatic embryo regeneration system for hypocotyl explants of Xinluzao 45, a widely planted variety in Xinjiang Province. [Result] Faint yellow callus was induced on a medium consisting of hormone combinations C1 (0.1 mg·L^－1 acetic acid dichlorobenzene oxide [2, 4-D] + 0.1 mg·L^－1 kinetin [KT]) or C5 (0.1 mg·L^－1 2, 4-D + 0.5 mg·L^－1 indo-3-butyric acid + 0.1 mg·L^－1 KT). The generated callus was able to successfully induce embryogenic callus on hormone-free medium containing doubled KNO3. The embryogenic callus then developed into somatic embryos and regenerated plants. Maximum rates of callus induction and regeneration were 92.2% and 40.3%, respectively. Although no significant difference was observed in the rate of callus induction of Xinluzao 45 hypocotyls between hormone combinations C1 and C5, the incidence of induced embryonic callus was higher on C1 than on C5. [Conclusion] The somatic embryo regeneration system developed in this study provides technical support that will facilitate Agrobacterium-mediated transformation of upland cotton Xinluzao 45.     

缓释氮肥对小麦后直播棉产量及氮素吸收利用的影响

【目的】研究缓释氮肥运筹对小麦后直播棉产量及氮素吸收利用的影响。【方法】2016―2017年以短季棉品种中棉所50为材料,采用小麦后直播的种植方式,设3个缓释肥氮素用量:45、90和135 kg·hm-2,2个施用时期分别为2叶期和4叶期。以常规氮肥尿素(纯氮90 kg·hm-2,CK1)和不施肥为对照(CK2)。【结果】缓释肥氮素90 kg·hm-2,并于2叶、4叶期施用产量较高,其中2017年籽棉产量显著高于其它处理,分别达4198.7和4037.8 kg·hm-2,比对照CK2分别高517.2和356.3 kg·hm-2,干物质积累量也表现为缓释肥氮素用量90 kg·hm-2于2叶、4叶期施用较高,其中2017年分别达到14090.5 kg·hm-2、13564.5 kg·hm-2,分别比对照CK2高12.6%和8.4%。氮素积累量表现相似的结果。氮素利用效率结果进一步表明,2叶期施缓释肥氮素用量45 kg·hm-2的处理氮素回收利用率(NARE)、氮素农学利用率(NAE)及氮素生理利用率(NPE)都最高,2叶期施缓释肥氮素用量90 kg·hm-2的处理其次,如2017年2叶期施缓释肥氮用量45 kg·hm-2处理的上述3个氮素利用效率分别为75.62%、23.68%、77.26%,施缓释肥氮素用量90 kg·hm-2处理则分别为60.9%、19.9%、46.6%,而对照CK2仅为53.79%、14.12%、40.91%。【结论】小麦后直播棉在2叶期一次性施用缓释肥氮素用量90 kg·hm-2能显著提高氮素利用效率,促进群体干物质生产并实现高产,同时达到轻简高效的目的。     

The Effect of Spraying Concentrated Biogas on Growth and Physiological Characteristics of Cotton Seedling

[Objective] The effect of concentrated biogas slurry on growth and physiological characteristics of cotton seedlings was studied in this experiment, and theoretical basis for the rational application of concentrated biogas slurry was provided. [Method] Potted cotton seedlings was sprayed by five different dosages of concentrated biogas slurry, the impact of different spraying quantity (163 mL·hm^－2, 326 mL·hm^－2, 489 mL·hm^－2, 668 mL·hm^－2, 815 mL·hm^－2) after spraying time (after spraying 2nd day, 4th day, 6th day) on cotton seedlings growth and physiological indexes were studied. [Results] The results showed that the suitable quantity of spraying of concentrated biogas slurry had promoting effect to the cotton growth and development, the excess concentrated biogas slurry could inhibit the growth of cotton seedlings. The plant height, dry weight per plant and leaf area of spraying 489 mL·hm^－2 processing are the highest, the average of two batches on the 6th day after spraying are 21.15%, 35.95%, 18.84% higher than CK, respectively. Spraying concentrated biogas slurry can improve cotton seedlings chlorophyll content, soluble sugar contents, soluble protein content. Spraying 489 mL·hm^－2 processing is the highest in both batches, the average of two batches is 18.84%, 24.03%, 3.16% higher than CK, respectively. The result of concentrated biogas slurry onseedlings leaves took effect quickly, especially in 0～4th days. [Conclusion] It is concluded that the suitable amount of concentrated biogas slurry has a positive effect on the growth and physiological characteristics of cotton seedlings, which is beneficial to the formation of strong seedlings of cotton and provides the basis for the later growth of cotton.     

秸秆还田对滨海盐碱地棉苗光合特性及生长的影响

为探讨秸秆还田对滨海重度盐碱地棉苗光合特性及生长的影响,设置增施有机肥、播前秸秆还田、冬前秸秆还田3个处理,测定了棉花苗期3个层次土壤含盐量、水分和容重,棉花叶片光合参数、叶片SPAD值以及干物质积累和棉花产量。结果表明,与对照相比,增施有机肥和秸秆还田的处理各个土层含盐量和容重明显降低,棉苗叶片LAI和SPAD明显增大,光合能力提高,干物质积累量、根冠比以及棉花产量明显增加。其中,冬前秸秆还田各土层含盐量低于2.00 g·kg-1,容重保持在1.15~1.40 g·cm-3,叶片SPAD值高于40.0,LAI提高65.5%,光合性能系数增高23.4%~92.8%,非光化学淬灭系数(NPQ)降低12.2%,干物质积累总量增大46.3%,根冠比提高56.5%,产量提高36.2%。因此,在本试验条件下,冬前秸秆还田更有利于滨海盐碱地改良及棉苗的正常生长。