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1.
Drought appears at flowering and boll formation for cotton frequently. However, reports on the impact of carbon dynamics in the subtending leaf on boll biomass under periodic droughts are limited. To investigate this, experiments were carried out with two cultivars (drought-tolerant: Dexiamian 1; drought-sensitive: Yuzaomian 9110), three water levels [soil relative water content (SRWC): control (75 ± 5)%, moderate drought (60 ± 5)%, severe drought (45 ± 5)%] and five drought durations (10, 17, 24, 31 and 38 days). A 38-day drought declined the net photosynthetic rate of subtending leaf, which could be collectively attributed to the reduction in carboxylation with reduced ribulose-1,5-bisphosphate carboxylase activity, and stomal limitation with decreased stomatal conductance, along with the damage of photosynthetic apparatus with depressed maximum and actual photochemical quantum yield, leading to lower starch content. A 38-day drought also increased the activities of sucrose phosphate synthase (SPS), sucrose synthase (Susy) and expressions of genes (GhSPS1, GhSPS2, GhSusA and GhSusB) associated with these enzymes, causing the accumulation of sucrose content, finally resulting in lower boll biomass. Some of the above parameters fully recovered under more than 17-day moderate drought or over 10-day severe drought, but boll biomass still decreased after re-watering. Under 10-day moderate drought, all aforementioned indices and boll biomass were completely recovered within 7 days of re-watering, and the recovery capacity of Yuzaomian 9110 was lower than that of Dexiamian 1. Therefore, rapid recovery of photosynthesis and decline in the subtending leaf sucrose content to pre-stress levels are important factors in lessening the impacts of drought on boll biomass and are indicative of cultivar tolerance to short-term moderate water deficit.  相似文献   

2.
Global warming could possibly increase the air temperature by 1.8–4.0°C in the coming decade. To forecast the effects of long‐term elevation of air temperature on sucrose synthesis in cotton leaves at different positions, field experiments with the treatments of ambient temperature (control) and elevated temperature (2–3°C) across cotton's boll forming stage were conducted in 2011 and 2012. Results showed that sucrose content in the fourth main‐stem leaves from the terminal (FMLT) during 10–17 days after treatment (DAT) and in the leaves subtending the cotton boll (LSCB) during 17–45 days post‐anthesis (DPA) was lower in the increased temperature treatment than control treatment, but starch content was higher, resulting in higher specific leaf weight (SLW). Lower sucrose content might be attributed to low ribulose‐1,5‐bisphosphate carboxylase‐oxygenase (Rubisco) and cytosolic fructose‐1,6‐bisphosphatase (cy‐FBPase) activities under elevated temperature for all tested leaves. Comparison of different fruiting branch (FB) positions, sucrose transformation rate just decreased in LSCB growing on FB2–3 and FB6–7. Compared with FB10–11, the leaves at FB2–3 and FB6–7 were more sensitive to the increased temperature, showing as that the changing amplitudes of SLW, sucrose content, starch content, initial Rubisco activity and cy‐FBPase activity were greater. Regarding different types of cotton leaves, the effects of elevated temperature on sucrose content, starch content and initial Rubisco activity in FMLT were obvious at the early stage (10–17 DAT), but were not obvious at the late stage. However, the effects were consistent in LSCB from 17 to 45 DPA. In addition, long‐term elevated temperature had smaller impacts on above indices in FMLT than LSCB. Sucrose phosphate synthase (SPS) and sucrose synthase (SuSy) activities were decreased by elevated temperature in FMLT at the early stage, but were increased in LSCB, suggesting that SPS and SuSy were the key enzymes between FMLT and LSCB in response to elevated temperature.  相似文献   

3.
The cotton (Gossypium hirsutum L.) crop is an indeterminate species that is most sensitive to drought stress during the flowering and boll-formation stage of development. To evaluate the effect of water deficit on fibre quality and carbon metabolism at different fruiting branches (FB), multiple controlled experiments were conducted. The cotton cultivar Siza 3 was used under three soil relative water content (SRWC): control (CK, SRWC (75 ± 5) %), moderate drought stress (MDS, SRWC (60 ± 5) %) and severe drought stress (SDS, SRWC (45 ± 5) %) treatment, imposed at the beginning of the flowering of FB6–7. Fibre quality was significantly affected by drought level and fruiting branch location on the plant. Compared to the CK, under MDS and SDS, sucrose content and sucrose synthase (SuSy) activity decreased prior to 24 days post-anthesis (DPA; the fibre elongation phase), which caused low fibre turgor pressure. This decreased the rate of fibre elongation and final fibre length. Moreover, from 24 to 38 DPA (during fibre thickening), low fibre sucrose content led to insufficient UDP-glucose (UDPG; uridine diphosphate glucose) for cellulose synthesis. Furthermore, more of the existing UDPG was allocated to the synthesis of callose instead of cellulose, which resulted in lower cellulose accumulation and decreased fibre strength. The magnitude of the drought stress effect on fibre qualities, as well as the formation process, was strongly influenced by fruiting branch position, where differences were most pronounced for fruiting branches further away from the base of the plant.  相似文献   

4.
This study aimed to illustrate the mechanism of sucrose metabolism in subtending leaves of cotton bolls and its relationship with boll weight under drought stress during flowering and bolling stages. The 2-year-long experiments were conducted using pools of upland cotton(Gossypium hirsutum L.) plants, NuCOTN 33B, subjected to drought stress (relative water content reduced naturally until the boll opening stage) on the day of anthesis of the middle fruiting branches (MFB), using well-watered conditions as the control. The net photosynthetic rate declined under drought stress in the boll's subtending leaf, respectively, and the decline range was MFB>upper fruiting branch (UFB)>lower fruiting branch (LFB). Drought stress increased the soluble sugar contents of subtending leaves at LFB and UFB but decreased them at MFB. Sucrose content was increased and starch content decreased concomitantly, indicating that drought facilitated the partitioning of photosynthate into sucrose. Drought stress also depressed the activities of sucrose phosphate synthase and sucrose synthase, while acid invertase activity was initially decreased and then increased. The changes of MFB and UFB exceeded those of LFB, indicating that sucrose synthesis was inhibited, the degradation was first inhibited then promoted, causing a reduction in the amount of sucrose available for export. As a result, the boll weight declined during drought, and the decline range was MFB>UFB>LFB. In conclusion, the decreased sucrose synthesis and the impaired sucrose efflux of subtending leaves of bolls were the main causes for decreased boll weight under drought conditions during flowering and bolling stages of cotton.  相似文献   

5.
【目的】棉铃疫病是严重危害棉花生产的铃部病害。本研究旨在优化棉铃疫菌(苎麻疫霉,Phytophthora boehmeriae)的人工接种方法并有效应用。【方法】在室内保湿培养条件下,比较了棉株不同部位健康成铃自身携带棉铃疫菌的情况;利用贴接棉铃疫菌菌盘的方法,比较了棉铃表面消毒和不消毒、有伤和无伤接种对棉铃疫病发病情况的影响;建立棉铃疫病人工接种方法并应用于防治棉铃疫病化学药剂筛选、棉花品种抗病性鉴定和棉铃疫菌致病力检测。【结果】田间棉株下部第1~3果枝铃的棉铃疫病发病率显著高于中部第4~6果枝铃、中部第7~9果枝铃和上部第10~12果枝铃;75%(体积分数,下同)酒精浸泡棉铃2 min能够有效杀死棉铃表面携带的棉铃疫菌和其他真菌等杂菌;有伤接种棉铃疫菌,棉铃疫病发病快且均匀。建立了棉铃疫病快速人工接种方法:选取棉株中部第4~9果枝上的健康带柄成铃,去掉苞叶,用75%酒精浸泡消毒2 min,在棉铃中上部铃缝处针刺接种棉铃疫菌,25℃保湿培养3~7 d即可完全发病。应用优化的棉铃疫病人工接种方法筛选、鉴定结果表明,12种化学杀卵菌剂中,对棉铃疫病防效理想的药剂为25%(质量分数,下同)甲霜·霜霉威可湿性粉剂、70%丙森锌可湿性粉剂和52.5%噁酮·霜脲氰水分散粒剂;16个棉花品种对棉铃疫病存在抗性差异;10个棉铃疫菌菌株中JP18-4的致病力最强,JP15-2对棉铃的致病力最弱。【结论】本研究优化建立了棉铃疫病人工接种方法。该方法在7 d内即可完成棉铃疫病相关试验的评价,为加快棉铃疫病防治药剂筛选、棉花品种抗病性鉴定和棉铃疫菌致病力检测提供可行的技术。  相似文献   

6.
Knowledge of genetic relationships between within‐boll yield components and fibre quality is essential for simultaneous improvement of lint yield and fibre quality in upland cotton (Gossypium hirsutum L.). Nine parents and their F1 progeny with reciprocals from a 3 × 6 factorial mating design were grown in 2008 and 2009. Seven within‐boll yield components and two boll morphological traits and the three fibre quality parameters were analysed based on a conditional additive/dominance (AD) genetic model. Results showed that boll length contributed to the largest proportion of phenotypic, additive and dominance variances for UHM length; seed index contributed to the largest proportion of phenotypic and additive variances for fibre strength; boll width made the largest contribution to phenotypic and additive variances and the second largest contribution to dominance‐by‐environment interaction variance for micronaire, indicating that they played an important role than the other traits for fibre length, strength and fineness/maturity, respectively. It is worthy of note that those correlations between boll shape and fibre quality apply only to the nine parents and the resultant hybrids in this study and do not imply a cause and effect relationship.  相似文献   

7.
汪霄  陈防 《棉花学报》2015,27(1):16-21
以钾高效和钾低效基因型棉花(HEG和LEG)为试验材料,研究了最优水肥(W1K1),干旱胁迫(W2K1),低钾胁迫(W1K2),干旱、低钾胁迫(W2K2)对其光合作用及水分、钾素利用率的影响。结果表明:干旱显著降低花铃期2种基因型棉花叶片净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr),导致蕾铃脱落,钾素利用率(KUE)降低,造成棉花减产。施钾促进叶片Pn及水分利用率(WUE)的提高,但基因型间存在差异,LEG叶片WUE与施钾量成正比,HEG相反。低钾胁迫下HEG的Pn、Tr下降,但Pn下降幅度小于Tr,WUE增大。较高的WUE有利于提高棉花Pn,降低蕾铃脱落率,促进钾素的高效吸收和运输。  相似文献   

8.
[Objective] The present study aimed to investigate how sucrose metabolism in the leaf subtending to cotton boll, within-boll yield components and fiber quality respond to varying planting dates. [Method] Two upland cotton lines A705 and A201 differing in cotton boll traits were field tested in 2016-2017. Two different planting dates were designed with early planting on April 12, 2016, and April 15, 2017, and late planting on May 6, 2016, and May 28, 2017, respectively. Dynamics of non-structural carbohydrates (sucrose, hexose, starch) and key sucrose metabolism enzymes in the leaf subtending to cotton boll were examined including vacuolar acid invertase, cell wall acid invertase, sucrose phosphate synthase and sucrose synthase. The differences between two planting dates were compared for within- boll yield components, fiber quality and sucrose metabolism related characteristics. [Result] Late planting lengthened the period of cotton boll maturation relative to early planting. Boll weight, seed mass per boll, seed index and fiber length were increased, and lint percentage and micronaire were decreased. Late planting reduced the activities of cell wall acid invertase and sucrose synthase responsible for sucrose degradation, and in turn led to the increment of sucrose concentration in the subtending leaves which might enhance the carbon supply to the opposite bolls. [Conclusion] Lower temperature due to late planting could contribute to the more full development of cotton bolls. Late planting is an alternative consideration in improvement of fiber quality in cotton cultural practices.  相似文献   

9.
Brassica rapa L. is a genetically diverse parent species of the allotetraploid species, oilseed rape (B. napus) and a potential source of drought tolerance for B. napus. We examined the effect of a 13‐day drought stress period during the early reproductive phase, relative to a well‐watered (WW) control, on subsequent growth and development in nine accessions of B. rapa and one accession of Brassica juncea selected for their wide morphological and genetic diversity. We measured leaf water potential, stomatal conductance, water use, and leaf and bud temperatures during the stress period and aboveground dry weight of total biomass at maturity. Dry weight of seeds and reproductive tissue were not useful measures of drought tolerance due to self‐incompatibility in B. rapa. The relative total biomass (used as the measure of drought tolerance in this study) of the 10 accessions exposed to drought stress ranged from 47 % to 117 % of the WW treatment and was negatively correlated with leaf‐to‐air and bud‐to‐air temperature difference when averaged across the 13‐day stress period. Two wild‐type (B. rapa ssp. sylvestris) accessions had higher relative total and non‐reproductive biomass at maturity and cooler leaves and buds than other types. We conclude that considerable genotypic variation for drought tolerance exists in B. rapa and cooler leaves and buds during a transient drought stress in the early reproductive phase may be a useful screening tool for drought tolerance.  相似文献   

10.
[Objective] A 2-year field experiment was conducted to determine the effect of a moderate drought regime in the early-stage on cotton yield, fiber quality and water use efficiency. [Method] An experiment was set up in 2015 and 2016 on the Qingyuan Experimental Plot of Hebei Agricultural University based on a split plot design with two main plots: (1) conventional irrigation (W1) and (2) drought (limited irrigation before sowing with no irrigation during the growing period, W2). Three sub-plots with different cotton cultivars were established: CCRI 50 (early maturity), Nongdamian 601 (ND 601, moderate earliness), and Jimian 958 (JM 958, intermediate maturity). [Result] (1) Drought stress affected the ratio of seasonal bolls. Under drought stress, the ratio of summer bolls decreased and that of autumn bolls increased. Because the precipitation peak in 2016 was higher than normal and mainly concentrated in July, which was later than in 2015, the ratio of autumn bolls increased in 2016. (2) Drought stress affected cotton yield but had no significant effect on fiber quality. Under moderate drought, the boll number per plant and boll weight of ND 601 and JM 958 decreased, the ratio of boll setting increased (P < 0.05), the boll weight of CCRI 50 increased, and the yields of all three cultivars decreased. Because CCRI 50 is an early-maturing cultivar and sensitive to water, its yield decreased significantly (41.0%). (3) Reducing irrigation by an appropriate amount was able to improve water use efficiency. The water use efficiencies of ND 601 and JM 958 averagely increased significantly, by 15.75% and 10.05%, respectively, between 2015 and 2016 under drought stress. The water use efficiency of CCRI 50 decreased significantly, by 15.9%, because of its early maturity and sensitivity to water stress. [Conclusion] Moderate irrigation has a significant effect on yield, fiber quality, and water use efficiency. Cotton yield losses caused by water stress can be ameliorated by making the best use of natural precipitation and by increasing planting density.  相似文献   

11.
在新疆气候生态条件下, 采用膜下滴灌植棉技术, 控制花铃期0~60 cm土壤滴水下限分别为田间持水量的45%(中度干旱)、60%(轻度干旱)和75%(正常供水, 对照), 滴水上限均为田间持水量, 研究不同程度干旱复水对棉花叶片光合特性及产量形成的影响。结果表明, 干旱降低了叶片净光合速率(Pn)和气孔导度(Gs), 中度干旱下叶片光化学猝灭系数(qP)、PSⅡ电子传递量子产量(ФPSⅡ)降低, 非光化学猝灭系数(NPQ)升高。复水后3 d内Pn和Gs恢复, 以轻度干旱恢复最快; ФPSⅡ和qP与Pn的变化相似; NPQ复水后1~2 d显著降低。从初花期至盛铃前期, 轻度干旱复水后光合物质累积量与对照无明显差异, 盛铃后期至吐絮期低于对照, 籽棉产量较低; 中度干旱复水后光合物质累积量及籽棉产量均最低。  相似文献   

12.
棉花花铃期土壤持续干旱胁迫对产量形成的调节效应   总被引：13，自引：6，他引：7  
蔡红涛  汤一  刁品春  荣利 《棉花学报》2008,20(4):300-305
 通过花铃期不同持续时间土壤干旱处理,研究干旱胁迫对棉花产量形成的影响。表明持续干旱对子棉产量影响以单株成铃数＞成铃率＞单铃重。短期干旱胁迫W1处理增加成铃数显示子棉增产,同步抑制下部内围铃棉纤维和棉子的物质积累量,解除胁迫后形成盛花结铃阶段产量潜载优势,极显著提高下、中部外围和上部内围铃子棉产量,实现增产;花后持续20 d以上干旱胁迫效应会延续至花后50 d,整体降低各部位棉铃的积累物质供应量,产量器官虽具干物质积累相对优势,但子棉产量潜载势降低,单株成铃数、单铃重趋降显示子棉减产;干旱胁迫对子棉产量的调控显示区位效应,降产效应随干旱延长显示由下而上、由内而外区位拓展态势,解除胁迫可获得一定产量补偿。  相似文献   

13.
This study aimed to evaluate the ability of Piriformospora indica to colonize the root of Chenopodium quinoa and to verify whether this endosymbiont can improve the growth, performance and drought resistance of this species. The study delivered, for the first time, evidence for successful colonization of P. indica in quinoa. Hence, pot experiment was conducted in the greenhouse, where inoculated and non‐inoculated plants were subjected to ample (40%–50% WHC) and deficit (15%–20%WHC) irrigation treatments. Drought adversely influenced the plant growth, leading to decline the total plant biomass by 74%. This was linked to an impaired photosynthetic activity (caused by lower gs and Ci/Ca ratio; stomatal limitation of photosynthesis) and a higher risk of ROS production (enhanced ETR/Agross ratio). P. indica colonization improved quinoa plant growth, with total biomass increased by 8% (controls) and 76% (drought‐stressed plants), confirming the growth‐promoting activity of P. indica. Fungal colonization seems to diminish drought‐induced growth hindrance, likely, through an improved water balance, reflected by the higher leaf ψw and gs. Additionally, stomatal limitation of photosynthesis was alleviated (indicated by enhanced Ci/Ca ratio and Anet), so that the threat of oxidative stress was minimized (decreased ETR/Agross). These results infer that symbiosis with P. indica could negate some of the detrimental effects of drought on quinoa growth, a highly desired feature, in particular at low water availability.  相似文献   

14.
Seed cotton yield and fibre quality are controlled by polygenes and highly influenced by the environment. Hence, selection merely based on yield is not effective. In order to enhance the yield potential of the cotton varieties, an understanding of the relationship among different characters is of more importance. Knowledge on the direct contribution of different characters to yield would be highly important for formulating a selection programme. Correlation and path coefficient analysis were carried out using 62 progenies of an interspecific backcross population (Gossypium hirsutum L. var. KC 3 x Gossypium barbadense L. var. Suvin) x KC 3. Genotypic correlation studies revealed that number of bolls per plant, boll weight, number of sympodia per plant, number of seeds per boll, seed index, lint index, days to first flowering, and plant height have a significant positive association with seed cotton yield per plant. Path coefficient analysis showed that number of bolls per plant contributed maximum direct effect to seed cotton yield per plant followed by boll weight and lint index. The highest positive indirect effect on seed cotton yield per plant was also observed through number of bolls per plant. This indicated that seed cotton yield per plant was highly influenced by number of bolls per plant directly and indirectly. Thus, a greater emphasis should be given to number of bolls per plant, boll weight, and lint index for increasing seed cotton yield per plant.  相似文献   

15.
Eleven cotton (Gossypium hirsutum L.) cultivars were evaluated for their growth and yield performance in Shihezi, Xinjiang, China, an area in Central Asia with short growing period in 1999 and 2000. In each cultivar the number of bolls per plant was low and the number of bolls per unit area was high. Each cultivar showed rather high seed and lint yields. The highest lint yield was Xinluzao 10 in both years with 1761 and 1809 kg ha?1. High yield ability of the cultivars in this study was attributed to large number of bolls per unit area with high lint percentage. Seed and lint yields had significant positive correlations with mean net assimilation rate, ratio of reproductive to vegetative organs and mean boll weight at earlier stages of boll growth, suggesting that early boll formation and successive partitioning of dry matter into bolls were important factors for boll growth in this study area.  相似文献   

16.
Higher than optimum temperatures during cotton's (Gossypium hirsutum L.) growing season is a common occurrence in cotton‐growing areas around the world with negative consequences on productivity. According to climate projections, night temperatures are expected to increase more than day temperatures. The objective of this study was to monitor and record the effects of higher than optimum night temperatures during cotton's early reproductive stage on physiological (photosynthesis, respiration and membrane damage) and biochemical (leaf adenosine triphosphate (ATP) levels, as well as glutathione reductase (GR) content and soluble carbohydrate concentrations of the leaf subtending the flower buds. Number, dry weight, carbohydrate concentrations and GR levels of flower buds were also measured at the end of the experiment. Growth chamber experiments were conducted using cotton cultivar ST 5288 B2RF and treatments consisted of normal day/night temperatures (32/24 °C) and high night temperatures (32/30 °C) for 7 days at squaring (approximately 4 weeks after planting). The results indicated that high night temperatures had an immediate effect on leaf respiration rates and membrane damage by significantly increasing them compared to the control and a similar pattern was observed on leaf photosynthesis and ATP levels that were markedly decreased. Leaf GR levels were also substantially increased under conditions of high night temperatures, in contrast to flower bud GR content which remained unaffected. High night temperatures had a significant effect on leaf carbohydrate concentrations resulting in significant decreases in hexose, sucrose and starch levels. Nevertheless, flower bud sucrose content was substantially increased under conditions of high night temperatures, while hexose content was decreased and starch concentrations remained unaffected. A detrimental effect of elevated night temperatures on the number of flower buds per plant and on the dry weight of flower buds was observed, and it was concluded that high night temperatures had a negative effect on cotton flower bud production due to disruptions on flower bud carbohydrate metabolism as a result of the insufficient GR response.  相似文献   

17.
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   

18.
Trees are the dominant species in agroforestry systems, profoundly affecting the performance of understory crops. Proximity to trees is a key factor in crop performance, but rather little information is available on the spatial distribution of yield and yield components of crop species under the influence of trees in agroforestry systems. Also, little information is available on how crop density may be exploited to optimize the yield in such systems. Here we studied the performance of cotton in jujube/cotton agroforestry. Field experiments were conducted in 2012 and 2013 in Hetian, Xinjiang, China. Cotton was grown at a row distance of 60 cm in three densities, 13.5, 18.0 and 22.5 plants m−2 in six m wide paths between tree lines in a jujube plantation. Plant density affected both cotton aboveground dry matter and yield significantly. The highest yield was attained at the intermediate density of 18.0 plants m−2 (20.0 plants m−2 corresponding in sole cotton), lower than the optimal density in sole cotton (25.0 plants m−2). Yield at the lower density was constrained by the low number of bolls per m2 as a direct consequence of the low density, whereas at the high plant density yield was constrained by a lower allocation of assimilates to cotton seed and lint, as a consequence of intraspecific and interspecific competitions. There were strong gradients in yield and yield components in relation to the distance from the tree rows. Leaf area and total dry matter of cotton in rows close to the tree lines were reduced, especially in the rows next to the trees. Moreover, biomass allocation to cotton fruits was reduced in these rows. Competitive influences from the trees on cotton performance extended two rows deep in a six-year old jujube stand, and even three rows deep in a seven-year old stand. Shading effects on cotton yield were compensated by increasing plant density as a result of greater boll numbers per unit ground area. Data from this study help guide the design of optimal plant density of cotton in jujube plantations and give insight in the spatial distribution and dynamics of competitive effects in agroforestry systems in general.  相似文献   

19.
以棉纤维比强度高的科棉1号、比强度中等的美棉33B 2个品种为材料,于2006-2007年在江苏南京设置大田分期播种试验,使棉铃发育处于不同温度条件,于棉株7～9果枝第1、2果节棉铃开花时喷施6-苄基腺嘌呤(6BA)和脱落酸(ABA),研究不同的铃期日均最低气温条件下6-BA和ABA对棉花产量和纤维品质的影响。结果表明:由晚播造成的低温降低了棉花产量及纤维品质。外施6-BA、ABA对棉株中部果枝铃铃重和纤维品质影响最大。正常播期下,外施6-BA可增加中部果枝棉铃铃重,外施ABA降低铃重,但二者对其纤维品质影响较小;迟播时,外施6-BA可提高中部果枝棉铃铃重,ABA处理的作用则相反,二者均可提高纤维长度和比强度、优化麦克隆值。不同的温度条件下,外施6-BA均提高了单株铃数、单株平均铃重和皮棉产量,外施ABA则降低了棉花单株铃数和产量。外施6-BA和ABA对高强纤维品种产量和纤维品质的影响较中强纤维品种更为明显。低温下,在棉铃发育初期喷施6-BA对改善棉纤维品质的效果最好。  相似文献   

20.
株型对棉株14C同化物生产及运转分配的影响   总被引：2，自引：0，他引：2  
运用 14 C示踪技术 ,研究了简化整枝与早打主茎顶心、少留果枝改变株型对 14 C同化物生产分配的影响。结果表明 ,简化整枝蕾期、花铃期果枝叶的光合作用强度和14 C同化量均低于对照 ,且　14 C同化物向主茎和果枝的分配比例也较对照降低。简化整枝早打主茎顶心 ,可提高花铃期果枝叶、叶枝叶的光合作用强度和 14 C同化物向叶枝的分配比例。反映到产量和产量构成因素上 ,表现为简化整枝主茎结铃减少 ,叶枝结铃可弥补其损失 ,单铃重和衣分略有降低 ;简化整枝早打主茎顶心增加了叶枝结铃数 ,且单铃重和衣分略有提高。但处理间的皮棉产量均无显著差异  相似文献   

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