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1.
脱叶剂对棉花叶片叶绿素荧光动力学参数的影响   总被引：5，自引：1，他引：4  
利用叶绿素荧光动力学测定技术,对脱叶剂的不同喷施时间条件下棉花叶片光能吸收、传递、转换特性及棉花产量进行了研究。结果表明喷施脱叶剂降低了棉花叶片的光合功能,降低了最大光化学效率(Maximum photochemical efficiency,Fv/Fm)及PSⅡ反应中心开放部分的比例,使初始荧光(Minimal fluorescence,Fo)上升、光合电子传递速率(Electron transport rate,ETR)和PSⅡ总的光化学量子产量(Photosynthetic quantum yield,Yield)降低,提高了非光化学猝灭系数(Non-radiant energy,NPQ),说明脱叶剂胁迫下棉花叶片发生了光抑制,PSⅡ复合体受到损伤伴随着光合电子传递受阻。吐絮率10%时喷施脱叶剂使棉花铃重、衣分、皮棉产量显著低于对照。吐絮率50%时喷施脱吐隆300 g·hm~(-2)+40%乙烯利1200 m L·hm~(-2),第25天棉花脱叶率为90.1%,吐絮率为99.87%,对棉花铃重、衣分及皮棉产量影响最小且更有利于促进叶片脱落和棉铃成熟。  相似文献   

2.
为明确脱叶剂喷施时间、频次对不同海岛棉品系脱叶、吐絮、产量性状及纤维品质的影响，以品系ZX102和ZX113为试验材料，采用三因素完全随机试验，设置3个喷施时间，2种喷施频次，分析不同海岛棉品系对不同处理的响应。结果表明：使用脱叶剂能明显提高脱叶率，吐絮率为40%和50%下两品系药后15 d左右时脱叶率已达90%且显著高于清水对照(P<0.05)；吐絮率40%和50%下使用脱叶剂使两品系马克隆值、上半部平均长度、比强度有所降低，表现为：CK>T2>T1，其中40%时T1处理的马克隆值显著低于CK(P<0.05)，不同处理下两品系铃重和籽指表现为：CK>T2>T1，其中40%时T1处理的铃重显著低于CK(P<0.05)。在海岛棉机械采收实践中，为保证产量和纤维品质，当田间吐絮率50%时可采用T2喷施方式来实现。  相似文献   

3.
【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。  相似文献   

4.
《棉花学报》2018,30(2):136-144
[Objective] The goal of this experiment was to study the effects of Verticillium wilt on photosynthetic characteristics and chlorophyll fluorescence characteristics of cotton seedlings, and to provide a theoretical basis for the identification of cotton resistance to Verticillium wilt at the seedling stage and the establishment of Verticillium wilt control techniques. [Method] Zhongzhimian 2 (Verticillium wilt resistant cultivar, ZZM-2) and Jimian 11 (Verticillium wilt susceptible cultivar, JM-11) were selected. Verticillium dahliae was inoculated at the two true leaves stage. The photosynthetic and chlorophyll fluorescence parameters of the last fully expanded young leaves were measured at 6 d after inoculation. [Result] (1) Under the stress of Verticillium wilt, the leaf area per plant, leaf water potential, photosynthetic pigment content and net photosynthetic rate (Pn) of cotton seedlings decreased, and the decreases in ZZM-2 were smaller than those in JM-11. (2) The decreased intercellular CO2 concentration and increased stomatal limitation value in the two test materials indicated that the decrease in Pn was mainly caused by stomatal limitation, and the decrease in chlorophyll a in ZZM-2 was smaller than the decrease in chlorophyll b, whereas the opposite trend was observed in JM-11. (3) The light response curve parameters of ZZM-2 were increased and theCO2 response curve parameters of ZZM-2 were decreased, but all parameters in JM-11 were decreased. For ZZM-2, the potential photochemical efficiency (Fv/Fm), the quantum yield of regulated energy dissipation (YNPQ) and the quantum yield of non-regulated energy dissipation (YNO) were increased slightly and the actual photochemical efficiency (YII) was decreased slightly, but the differences in these four indexes between diseased plants and healthy plants was not significant; however, the variable fluorescence yield (Fv) was significantly decreased. For JM-11, Fv, Fv/Fm, YII and YNPQ were significantly decreased, and YNO was significantly increased. (4) Fv/Fm in leaf lesion sites decreased, but that in non-lesion sites did not decline or even showed a slight increase. [Conclusion] Verticillium wilt resistant cultivars with higher photosynthetic capacity and carbon assimilation ability could reduce the effects of Verticillium wilt on photosynthetic characteristics and reduce the impacts on cotton yield and quality.  相似文献   

5.
新疆机采棉花实现叶片快速脱落需要的温度条件   总被引：5，自引：0，他引：5  
随着机采棉的快速推进,籽棉含杂率过高导致清理工序过多及纤维不必要的损伤。新疆棉区棉花生长后期的热量资源有限,如何合理喷施脱叶催熟剂是改善原棉品质的关键技术措施。本研究采用分期喷施脱叶催熟剂的方式,探讨了温度变化对棉花叶片脱落率的影响及实现棉花叶片快速脱落需要的温度条件。结果表明,在喷施脱叶催熟剂后(7.0±1.0)d内,棉花叶片脱落率最高,达55%～79%,且与最高温度和每日≥12°C有效积温呈显著的线性关系。若要在喷施脱叶催熟剂后(7.0±1.0)d内实现>55%的叶片脱落率,则应满足该时间段最高温度大于27.2°C、每日≥12°C有效积温大于7.0°C·日的要求。因此,喷施脱叶催熟剂后(7.0±1.0) d内是实现良好脱叶效果的关键时间段,期间的最高温度和每日≥12°C有效积温则是影响的关键因素。  相似文献   

6.
氮肥对大麦灌浆期叶片光合性能的影响及其相关性分析   总被引：1，自引：0，他引：1  
为探究氮肥对春大麦叶片光合性能的影响,以蒙啤3号和蒙啤5号两个品种为材料,研究不同施氮水平下内蒙古东部灌区春大麦灌浆期间叶片叶绿素（Chl）含量,叶绿素荧光参数（最大荧光Fm、最大光化学效率Fv/Fm、光化学猝灭系数qP）,光合参数（净光合速率Pn、气孔导度Gs、蒸腾速率Tr）的动态变化及其相关性。结果表明:随着灌浆时间延长,不同氮肥处理两品种大麦叶片Chl含量、Fm、Fv/Fm、qP均呈先升高后降低的趋势,Pn、Gs、Tr均呈下降趋势;随着施氮水平升高,叶片Chl含量、Fm、Fv/Fm、qP、Pn、Gs、Tr均逐渐升高。相关分析结果显示,叶片Chl含量、Fm、Fv/Fm、qP、Pn、Gs、Tr间均呈极显著正相关关系。显示增施氮肥可促进大麦灌浆期间叶片光合性能。本研究为优质高产大麦生产实践提供理论依据。  相似文献   

7.
本研究旨在通过梅雨前后自然光强明显变化的情况下对水稻叶片光氧化突变体812HS与野生型812S的PSII光化学活性、抗氧化酶活性等生理特性的比较研究,探讨812HS易受光氧化损伤现象的光合生理原因。结果表明,大田自然光照出现强光照前,812HS与812S的叶绿素含量、PSII活性、光合磷酸化活性、净光合速率、抗氧化酶活性和活性氧含量均无显著差异。自然强光照开始(梅雨结束)一段时间后,两种水稻的上述各项指标都发生了明显的变化。突变体812HS的叶绿素含量、PSII活性、非循环式光合磷酸化活性和净光合速率均较812S明显降低。高光强下812HS叶片中抗氧化酶CAT和POD活性的上升幅度则小于812S,从而使其体内富集了更多的O2?、H2O2和MDA。光氧化突变体812HS对高光照强度较敏感的PSII活性和较低的CAT、POD活性可能是其发生叶片光氧化现象的生理成因。  相似文献   

8.
[Objective] This study elucidates the responses of different mainstem leaves on cotton to defoliant thidiazuron and reveal the underlying mechanisms. [Method] Cotton plants were raised hydroponically. At the ten-leaf stage, 4.54 mmol·L－1 thidiazuron was evenly applied to all mainstem leaves, the youngest full-expanded leaf (the fourth leaf from apex) and the youngest leaf (the first leaf from apex). Then, the progress of abscission zone formation and shedding of each leaf was observed, and the expression level of genes related to ethylene synthesis and signal transduction in the fourth and first leaf from apex was analysed. [Result] The abscission zone developed in the following sequence: the first leaf from the top, then the lowest leaves (the ninth or tenth leaf from the top, 35-40 days old), and the fourth leaf from the top. However, the leaf abscission was in a different order: the earliest was the first leaf from apex, then the fourth leaf from apex, and the latest was the lowest leaves which were prone to wither and stick to the stalk. The GhACS1 expression was up regulated in both the first leaf and the fourth leaf from apex within 24 h after thidiazuron treatment. However, the expression of this gene changed more rapidly and sharply in the first leaf from the top than that in the fourth leaf from the top. In addition, the expression of GhACO1 (ethylene synthesis gene), GhEIN3 and GhERF23 (ethylene signal transduction genes) was significantly increased up to ten times in the first leaf from the top, whereas the expression of these genes did not change in the fourth leaf from the apex. [Conclusion] After exposed to defoliant thidiazuron, the time of the abscission zone formation of different leaves on cotton main stem is different, and the order of shedding is not consistent with that of abscission zone formation. The youngest ready to expand leaf abscises earlier than the youngest fully expanded leaf after thidiazuron treatment, which is possibly associated with the rapid expression change of genes related to ethylene synthesis and signal transduction in the former.  相似文献   

9.
《棉花学报》2018,30(2):155-163
[Objective] The purpose of this study was to examine potential drought tolerance mechanisms in cotton (Gossypium hirsutum L.). Biochemical (antioxidant, protein and compatible osmolyte) and physiological (photosynthesis) responses to drought stress during the flowering and fruiting stages were examined. [Method] Using two cotton genotypes (A001 and A705) with different drought tolerance, a pot study was conducted in 2016 with treatments consisting of control (well-watered) and water stress. Water stress treatment was designed as withholding water from the pots until stomatal closure followed by limited water supply for 25 days where water-stressed plants received 40% of the optimum quantity of water. Measurements were made on soluble protein, proline and malonaldehyde (MDA) concentrations, peroxidase (POD) activity and photosynthetic characteristics (net photosynthetic rate Pn, transpiration rate E, stomatal conductance Gs) during the period of water stress. [Result] The soluble protein concentration was decreased and POD activity and MDA level were increased in the leaf subtending cotton boll of A001 under water deficit when compared with the control, but no response was observed in A705. Proline level responded to water deficit inconsistently between the two genotypes and across all sampling dates. Water stress significantly decreased Pn, E and Gs in the main stem leaves for both A001 and A705. [Conclusion] The results indicated that POD, soluble protein and MDA are involved in A001 and A705 responses to water deficit, and A705 is more tolerant to soil drought than A001.  相似文献   

10.
[Objective] Under the same cultivation conditions, we explored the differences in photosynthetic characteristics between upland cotton and sea-island cotton, and their dry matter and nitrogen accumulation and distribution patterns during the blooming period, to provide a theoretical basis for irrigation and fertilization of island cotton. [Method] Using Xinluzhong 75, Xinluzhong 54, Xinhai 35 and Xinhai 48 as materials, we tested the net photosynthetic rate (Pn), leaf temperature, dry matter accumulation and nitrogen absorption and distribution characteristics under the same management conditions. [Result] After the flowering stage, when compared with island cotton, the Pn of upland cotton was higher, but the leaf temperature and light illumination were lower. However, the difference in effect of stomatal conductance (Gs) on Pn between island cotton and upland cotton was small. The dry matter accumulation of shoots and the daily accumulation of shoots and reproductive organs in the whole growth period were higher for upland than for island cotton, with a lower dry matter proportion of reproductive organs in the early growth period, and higher in the late period for upland than for island cotton. When compared with Xinhai 48, the initiation of rapid nitrogen accumulation of Xinluzhong 54 was later and its duration was shorter, but the maximum nitrogen accumulation rate was higher; however, the initiation of rapid accumulation time of reproductive organs was later, and its rapid accumulation duration was longer. [Conclusion] The dry matter output efficiency, accumulation in reproductive organs and nitrogen accumulation in the later growth period of island cotton were lower than those in upland cotton. Therefore, under production conditions, the proportions of water and fertilizer use should be increased for island cotton according to different regions.  相似文献   

11.
渍水和高温是长江中下游地区棉花生育中后期的主要气象灾害。2011和2012年在桶栽栽培条件下,研究了棉花花铃期功能叶光合特性、膜脂过氧化代谢对渍水(土表积水2~3 cm,7 d)、高温(7 d,每天持续6 h)及其复合胁迫的响应差异及其与产量的关系。结果表明,渍水、高温单独处理均增加了棉花主茎倒4叶超氧化物歧化酶(Superoxide dismutase,SOD)、过氧化物酶(Peroxidase,POD)活性和丙二醛(Malonaldehyde,MDA)含量。渍水和高温共同处理导致SOD活性降低,POD活性迅速增强和MDA含量急剧增加。渍水、高温及渍水+高温均降低了叶片SPAD值、光系统II最大光化学量子产量(Maximal photochemical quantum yield of photosystem II,F_v/F_m)和潜在光化学活性(Potential photochemical activity of photosystem II,F_v/F_0);同时降低了叶片净光合速率(Net photosynthesis rate,P_n)、气孔导度(Stomatal conductance,C_s)和蒸腾速率(Transpiration rate,T_r),增加了胞间二氧化碳浓度(Intercellular CO2concentration,C_i);减少了单株成铃数,降低了铃重,进而降低了籽棉产量,而对衣分影响不明显。从产量受害程度来看,渍水+高温(23.0%)渍水(17.1%)高温(9.8%)。除Ci外,SPAD值(叶绿素含量)、P_n、T_r、C_s、F_v/F_m及F_v/F_0与产量均呈显著正相关关系,其中SPAD值与产量的相关性最好。可将功能叶SPAD值作为作物响应逆境胁迫的敏感指标,应用到棉花抗逆能力评价和气象灾害减产评估之中。  相似文献   

12.
[Objective] Chemical defoliation is a necessary technical measure for machine-harvested cotton, and the effect of chemical defoliation directly affects the efficiency of mechanical-picking and fiber quality. Study on the molecular mechanism of defoliant in regulating defoliation could effectively guide the screening and improvement of defoliant-sensitive cotton germplasms. [Method] In this study, 200 cotton accessions were collected and planted in greenhouse, and treated with defoliant at the early flowering stage. Different varieties with high or low sensitivity to defoliant were selected according to the defoliation rate on the 4th day after treatment. The selected cotton varieties were also treated with defoliant at the boll opening stage in the field, and the defoliation rate on the 7th day after treatment was calculated. Meanwhile, samples from the abscission zone of the selected varieties were collected on the first and third day after treatment. And the expression of ethylene-, cytokinin- and hydrolase- related genes were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). [Result] Six defoliant sensitive and 6 insensitive varieties were selected from greenhouse and field tests. According to the qRT-PCR results, cytokinin-related genes, ethylene-related genes and hydrolase-related genes showed different expression patterns following defoliant treatment in different varieties, and most of these genes showed significant different expression in the defoliant sensitive and insensitive varieties. [Conclusion] This study indicates that different cotton germplasms respond to differently to defoliant, which might be the result of differential expression of cytokinin- and ethylene-related genes.  相似文献   

13.
将“延薯4号”单叶节茎段转入白光、红光、蓝光、红蓝光（4:1）下,测定了腋芽薯结薯特性、蔗糖和淀粉含量及光合性能等指标。结果表明,蓝光处理腋芽薯形成最早,单薯重和结薯率最高;在腋芽薯形成过程中,叶片蔗糖含量、干物质含量、叶绿素a（Chla）、叶绿素b（Chlb）、净光合速率（Pn）、相对电子传递速率（ETR）、光化学猝灭系数（qP）、实际量子产量（YPSⅡ）显著高于其他光质处理;红光处理叶片的蒸腾速率（Tr）、胞间二氧化碳浓度（Ci）、气孔导度（Gs）显著高于其他光质处理,蓝光处理最低;相同扦插时间叶片的潜在最大光能利用率（Fv/Fm）在不同光质处理间无显著性差异。基于上述结果,蓝光为诱导马铃薯单叶节茎段腋芽薯的理想人工光源。  相似文献   

14.
在北疆气候条件下,为明确棉花对不同施氮量下增效缩节胺[DPC+,25%甲哌鎓(1,1-dimethylpiperidinium chloride, DPC)水剂]化学封顶效应的响应,以新陆早53号为试验材料,在150(N1)、300(N2)和450(N3) kg hm~(–2)施氮水平下,以人工打顶(P0)为对照,研究DPC+剂量[450(P1)、750(P2)和1050(P3) mL hm~(–2)]对棉花叶绿素含量(Chl)、叶面积(LA)、气体交换参数、叶绿素荧光参数及干物质累积与分配的影响。结果表明,同一DPC+剂量下,随施氮量增加, Chl、LA、气体交换参数、叶绿素荧光参数和生殖器官干物质(RODM)均呈现先上升后下降的趋势;同一施氮量下,上述参数因DPC+剂量不同呈不同变化趋势,其中N1水平下以P1处理、N2水平下以P2处理、N3水平下以P3处理表现出较高的RODM、Chl、净光合速率(Pn)、实际光化学效率(ФPSII)、电子传递速率(ETR),较低的非光化学淬灭(NPQ)。DPC+与施氮量互作表现为,与其他处理相比, Chl、Pn、蒸腾速率(Tr)、气孔导度(Gs)、ФPSII、ETR、RODM在N2P2处理下分别提高了15.52%、29.39%、27.97%、36.77%、23.28%、23.55%、8.41%～22.24%, NPQ降低了34.54%。相关分析表明,干物质累积和Chl、LA、Pn、Gs、ФPSII均呈显著正相关,与NPQ呈极显著负相关。因此,在喷施DPC+(750 mL hm~(–2))条件下,适量追施氮肥(300kghm~(–2))能改善棉花光合性能,在增加干物质累积的基础上,促进了光合产物向生殖器官分配。  相似文献   

15.
[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 (Fv/FM) and photosynthetic performance index on absorption basis(PIABS) increased significantly. PIABS 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.  相似文献   

16.
以海陆渐渗系13-1×辽棉12组配的195个单株的F2群体为作图群体,利用SSR(Simple sequence repeat)标记和Join Map3.0软件构建遗传连锁图谱,构建的遗传连锁图谱包含39个多态性标记、13个连锁群,该图谱总长1174.4 c M,覆盖棉花基因组的26.7%,利用Ici Mapping完备区间作图法对F2:3家系进行相关性状的QTL定位,共检测到30个叶绿素荧光参数、7个叶片干物质含量、6个叶面积指数、1个叶绿素含量的QTL位点,分布在8条染色体上,在同一染色体共标记区间内存在多个性状的QTL,部分位点加性遗传效应来自同一亲本,与干物质含量、最大光化学效应相关的QTL位点在3条染色体上不同标记区间内重复出现,与叶面积指数、最大光化学效应相关的QTL位点在4条染色体上不同标记区间内重复出现,表现出遗传上的一因多效或基因连锁效应,可用于高光效聚合育种。  相似文献   

17.
盐胁迫下棉花K~+和Na~+离子转运的耐盐性生理机制   总被引：3，自引：2，他引：1  
为了探究棉花的耐盐机制,以中棉所49、中棉所35和中51504为材料,研究了盐胁迫对棉花幼苗的生长及K+/Na+平衡生理的影响。结果表明,150 mmol·L-1 Na Cl处理对幼苗的生长具有明显抑制作用,降低了叶片的光合速率(Pn)、PSⅡ实际光量子产额(ΦPSII)和电子传递速率(ETR),增加了非光化学荧光猝灭系数(q N)。与中棉所49和中棉所35相比,中51504的干物质累积受盐胁迫影响最小,且保持较高的Pn、ΦPSII、ETR和q N值及较低的ETR/Pn值。盐胁迫提高了棉花组织中Na+的浓度,降低了K+的浓度;但中51504组织中保持了相对较低的Na+浓度和较高的K+浓度,维持了较高的K+/Na+比;通过非损伤微测技术(NMT)测定的离子流结果也表明,中51504的根系对Na+有较强的外排能力,而对K+有较强的保留和向地上部转运能力。能够有效地调节Na+和K+的跨膜转运进而维持K+/Na+平衡是棉花耐盐的重要生理机制之一。  相似文献   

18.
棉花脱叶催熟剂对纤维品质的影响及应用时间的确定   总被引：2，自引：0，他引：2  
棉花脱叶催熟技术是实现棉花机械采收的重要前提,确定脱叶催熟剂喷施时期及标准对实现良好的脱叶和催熟效果至关重要。本研究采用分期喷施脱叶催熟剂的方式,探讨了脱叶催熟剂对纤维品质的损伤程度,及与棉铃铃期之间的定量关系。结果表明,脱叶催熟剂对纤维长度的影响在品种间存在差异, 46%～69%的供试品种纤维长度较对照下降或持平,另有31%～54%的品种纤维长度反而较对照增加,所有品种纤维长度较对照平均仅降低0.2%～1.2%。纤维比强度受脱叶催熟剂的影响较为明显,其损伤量(处理与对照的差值)集中分布在-4～0 cN tex~(-1)之间。脱叶催熟剂对纤维比强度的损伤程度与喷施时间有关,铃龄30 d时喷施损伤大,铃龄37 d时喷施损伤减小,且有61%供试品种的比强度较对照平均增加了1.1cN/tex。脱叶催熟剂对纤维比强度的损伤量随棉铃铃期延长而加剧,因此可根据"脱叶催熟剂喷施时棉铃的铃龄与铃期的比值(Rd/b)"这一指标确定脱叶催熟剂的喷施时间。此外,棉铃铃期与棉铃体积、棉铃体积与纤维比强度均呈显著正相关关系。如要生产比强度31 cN tex-1的棉花纤维,所选品种的棉铃体积应31.8 cm3、棉铃铃期应60.0 d,且要在Rd/b0.68 (铃龄40.9 d)后喷施脱叶催熟剂(可控制纤维比强度损伤量小于0.5 cN tex~(-1))。  相似文献   

19.
为探明谷子和玉米对烟嘧磺隆胁迫差异的光合生理机制,采用盆栽试验,选用谷子（张杂10号和晋谷21号）及玉米（迪甜8号和农大108号）为试验材料,在四叶一心期喷施5个不同剂量的烟嘧磺隆,分别在处理后7d和15d测定幼苗株高、叶面积、SPAD值、净光合速率（Pn）、气孔导度（Gs）、蒸腾速率（Tr）、胞间CO2浓度（Ci）、叶片最大光化学产量（Fv/Fm）、实际光化学效率[Y(Ⅱ)]、光化学猝灭系数（qP）和非光化学猝灭系数（NPQ）的变化。结果表明,除7.5g/hm2的烟嘧磺隆处理之外,张杂10号、晋谷21号和迪甜8号的株高、叶面积、SPAD值、Pn、Gs、Tr、Fv/Fm、Y(Ⅱ)和qP在用药后7d和15d时均显著低于对照,各指标在用药浓度15.0~60.0g/hm2处理之间的下降幅度均随烟嘧磺隆剂量的升高而增大;而Ci和NPQ却呈相反趋势。在15.0~120.0g/hm2处理之间,处理后7d和15d农大108号的所有指标均与对照差异不显著。综上所述,谷子对烟嘧磺隆的抗性弱于玉米,品种间也存在差异,部分原因是烟嘧磺隆显著降低了敏感品种叶片的叶绿素含量,虽然增加了光能热耗散,但PSⅡ功能还是受到抑制,导致光合能力下降。  相似文献   

20.
为筛选适宜于新疆奎屯垦区棉花的最佳脱叶催熟剂品种,开展了不同脱叶催熟剂对棉花脱叶效果及产量品质影响的田间小区试验。结果表明,至喷施后20d,所有脱叶催熟剂处理的叶片脱落率均达到70%以上,且T1、T2与T3、T4棉花叶片脱落率差异不大,但T1、T2处理均显著高于单施乙烯利处理。各处理棉铃吐絮率均在90%以上,且不同脱叶催熟剂处理间差异不大,说明所有脱叶催熟剂的催熟效果均较好。喷施脱叶催熟剂后棉花产量、单铃重、衣分、子指、绒长、整齐度指数、断裂比强度、马克隆值、短纤维指数、棉纤维成熟度比等指标较对照无明显差异,说明喷施脱叶催熟剂对棉花产量及品质影响不大。从喷施次数来看,2次喷施的脱叶和吐絮效果略优于1次喷施,但差异不大;棉花品质较1次喷施有轻微降低。因此,综合比较来看,T1处理的脱叶、吐絮效果均较好,且瑞脱龙价格适中,适宜在新疆奎屯垦区大面积推广。  相似文献   

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