湘杂棉8号在不同密度条件下棉株的成铃分布

以湘杂棉8号品种,设6个不同密度处理3次重复,从纵向、横向和圆锥体顺序比较其成铃分布状况。结果表明：各处理成铃率下部高于中部、中部高于上部;内围铃高于外围铃;单株成铃率以12000株/hm^2成铃率最高为42．6％,57000株/hm^2成铃率最低为28．2％;圆锥体成铃率,第1圆锥体以12000株/hm^2和21000株/hm^2两处理的成铃率最高,达到90％,第2、3圆锥体成铃率以12000株／hm^2、21000株／hm^2成铃率高,均超过70％,第4．10圆锥体成铃率随着密度、圆锥体序数的增加而逐渐降低,12000株／hm^2在第5圆锥体的成铃率达到50％以上。     

鲁棉研28号不同种植密度的棉铃空间分布研究

试验设5种不同种植密度处理,研究鲁棉28号棉株成铃分布的特点。结果表明,在试验设计的密度范围内,株高随密度的增加略有升高、果枝始节位随密度的增加也略增加;单株果枝数和单株结铃数随密度增加而减少,且随着密度的增加,上部铃、中部铃和内围铃的比例增大,下部铃和外围铃的比例减少。     

种植密度对棉花产量构成、成铃和棉铃性状分布的影响

 为了研究种植密度对棉花产量构成、成铃和棉铃性状分布的影响,探索使棉花群体在最佳结铃期和最佳结铃部位成铃的栽培技术措施,2008年和2009年在安阳进行了棉花密度试验。分析结果表明,低密度处理的单铃重和单株铃数较高,高密度的单位面积铃数较多,而密度适中时单位面积产量最高。下部和中部内围单位面积成铃数较多,成铃中以伏桃和秋桃为主;单株伏桃和秋桃在低密度时较大,而群体成铃数在各个时期均以高密度较高。下部和中部内围的单铃重在整个棉株空间中处于中等水平,低密度时最高。下部和中部内围成铃率较高,低密度处理最高。铃长、铃直径和铃体积在棉株的中部和内围最大;棉铃直径对铃体积的影响高于铃长,而棉铃体积对铃重的影响最大     

不同类型土壤棉花产量构成因素及棉铃空间分布研究

研究了膜下滴灌不同类型土壤棉花产量构成因素及棉铃空间分布规律。结果表明：产量构成各因素与皮棉产量之间均为正相关关系,且子棉与皮棉、铃数,皮棉与衣分、子数、地上干重、铃重,子数与地上干重的相关系数达极显著水平。壤土结铃能力最强,其次为粘土,单株成铃最少的是沙土地。从棉花不同果枝结铃的空间分布看,中部果枝结铃数高于棉株下部和上部,其中以壤土最高。不同类型土壤的棉田应进一步提高棉铃中部果枝成铃率,以提高棉花的品质;并进一步挖掘上部铃和外围铃的潜力,以提高棉花的产量。沙土地,应充分提高棉株的上部成铃率。     

杂交棉中棉所57主要经济性状空间分布规律研究

对2009年新引杂交棉品种中棉所57不同铃位主要经济性状在遗传变异、遗传典型相关分析和聚类分析等方面的研究结果表明,提高中部和上部内围铃的铃重,特别是增加中部和下部外围铃的有效成铃数,是获得高产的先决条件。     

塔里木棉区育苗移栽杂交棉棉铃空间分布特性

在大田条件下,采用不同移栽方式和移栽密度研究了塔里木棉区育苗移栽杂交棉棉铃空间分布特性。结果表明,不同移栽方式下,穴盘移栽的株高、果枝始节、单株铃数都大于裸苗移栽,铃重、单株皮棉产量的空间分布存在较大差异。具体表现为:穴盘移栽的上、中位铃及内围铃性状均优于裸苗移栽,而下位铃、外围铃间差异均不明显。不同密度处理间表现为:随密度的增加,果枝始节增高,果枝数、果节数和单株结铃数均减少。棉铃分布表现为随密度的增加上部、中部铃和内围铃所占比例均增大,下部铃和外围铃所占比例均减少。     

早期揭膜对棉花生育前期土壤水热微环境及其成铃的影响

探索早期揭膜对棉田耕作层土壤水热微环境变化及其对棉株成铃的影响,为实现棉花早期揭膜,减少地膜污染提供理论依据。田间自然条件下,以新陆中41号为研究对象,设早期揭膜（80%棉苗子叶出土展平后揭膜）和全生育期覆膜2个处理。测定不同处理棉田耕作层5 cm、10 cm、15 cm、20 cm、25 cm土层在10：00、13：00、20：00的温度、含水量以及棉株生育时期、成铃分布等指标;分析不同处理下棉田土壤水热微环境及棉株成铃变化。结果表明：早期揭膜处理较全生育期覆膜处理耕作层土壤温度略低,降幅2.0～2.5 ℃,且不受耕作层土壤深度层次影响;早期揭膜导致表层0～10 cm土壤的降温幅度不随时间推移而变化;与全生育期覆膜相比,早期揭膜主要导致表层0～15 cm土壤含水量降低,但这种差异随时间推移和土层深度增加而减小;早期揭膜对棉花出苗期至开花期的时长影响不大,但会降低棉株外围第2～3果节成铃率,其中上部和下部果枝尤为明显。综上所述,早期揭膜主要对棉田0～15 cm耕作层土壤水热微环境造成影响,表现为土壤温度及含水量长时间持续降低,但对15～25 cm土壤水热微环境影响较小;早期揭膜会明显降低棉株外围成铃率。     

环境温度与棉花蕾铃脱落的相关分析

当棉花的品种和田块一经确定下来,其籽棉产量的高低则主要取决于单位面积总成铃数和单铃籽棉重。生产实践表明,在一定生产水平下,单铃籽棉重变化相对较小,而单位面积上总成铃数变化则较大。目前大面积生产蕾铃脱落率很高,一般为60～70％,严重的可达80％以上,从而限制了单位面积产量的提高。棉花蕾铃脱落与许多因子有关。本文利用在南昌莲塘对沪棉204棉花品种的     

不同海岛棉品种蕾铃脱落规律初步研究

为研究海岛棉全生育期内不同品种及同一品种不同果枝部位蕾铃脱落动态变化及其差异，对4个品质和产量性状有差异的海岛棉品种蕾铃着生、脱落情况进行连续观察。结果表明：落蕾高峰期在6月下旬，以中部果枝落蕾较多；落铃高峰期在7月中下旬，以上部果枝落铃较多。所有品种的落铃率均高于落蕾率，蕾铃总脱落率与果枝数均具有较高的相关性。丰产型海岛棉品种蕾铃脱落率低于优质型海岛棉品种。     

北疆棉区棉花蕾铃脱落规律的初步研究

通过３ 年（１９９６～１９９８ 年）系统调查研究结果表明,北疆棉区棉花蕾铃脱落率达８０％ 以上,且落蕾率高于落铃率。落蕾在现蕾６ 天后直到开花前比例较大,而落铃主要集中在开花后１２ 天以内。蕾铃脱落的主要时期出现明显的峰值,随年份不同而有所不同。中部果枝现蕾较多,脱落率也较高;同一果枝第一果节以落铃为主,第二果节以落蕾为主。栽培措施、气候条件与棉花的蕾铃脱落有极其密切的关系。     

杂交棉F1代主要经济性状的相关及通径分析

以43份杂交棉F1代为研究对象,时各杂交组合主要性状竞争优势、相关系教及通径系数进行分析.结果表明:杂交棉F1代中皮棉产量、单株铃数和表分都有较强的竞争优势;时皮棉产量直接作用较大的性状为单株铃数、衣分和单铃重,对F1代的筛选应注重对这几个性状选择,以获得强优势的杂交组合.     

应用SAS/Graph模块分析棉铃空间分布情况

为解决棉铃空间分布传统分析展示不直观问题,运用SAS/Graph模块,可视化地展示棉铃空间分布情况。结果表明:中部果枝第一节位是成铃的关键区域,其次为中部果枝的第二节位;棉铃空间分布试验的3种密度均表现为中部果枝成铃率较高,下部果枝和上部果枝随密度增加成铃率降低,且随着密度增大成铃集中区域的主茎节位数下移。因此,为提高棉花产量,在保证中部果枝第一节位成铃的前提下,可从提高初始1~2台果枝的成铃率入手,当棉田实际保留株数较少时,可采取适当措施来保证果枝第二节位的成铃,不鼓励单果枝成铃三个及以上。     

Effect of trans-Bacillus thuringiensis gene on gibberellic acid and zeatin contents and boll development in cotton

Two experiments were conducted to investigate the effect of the Bacillus thuringiensis (Bt) transgene on gibberellic acid and zeatin contents and boll development in cotton using two types of Bt-transformed cultivars. In the 2003 study, boll size and weight, gibberellic acid 3 (GA₃) and zeatin (ZR) contents were investigated from 3 to 45 days after flowering (DAF). In 2004, the flowers were sprayed with GA₃, 6-benzyl adenine (6-BA) or a combination of both, and responses in boll size and weight, and endogenous GA₃ and ZR contents were determined. In comparison to the common parent, Simian 4, overall boll size and weight were lower for the conventional Bt cultivar, Sikang 1, but higher for the hybrid Bt cultivar, Sikang 3. Similarly, the boll GA₃ and ZR contents of Sikang 1 were lower than those of Simian 4, while those of Sikang 3 were higher than Simian 4. The largest difference between Sikang 1 and Simian 4 for boll GA₃ and ZR contents were 18.5 and 25.5%, respectively, observed at 17 DAF. The largest difference between Sikang 3 and Simian 4 for boll GA₃ and ZR contents were 25.5 and 85.7% at 31 DAF respectively. Application of GA₃, 6-BA or a combination significantly increased boll size and weight for the conventional Bt cultivar and Simian 4, but did not have a significant effect on these characteristics of the hybrid cultivar Sikang 3. GA₃ and ZR contents of the conventional Bt cultivar Sikang 1 were also significantly increased by application of these treatments. The combined application of GA₃ and 6-BA tended to have a larger effect than the application of either of them separately, but the differences were statistically not significant. These results suggested that the lower boll GA₃ and ZR contents, which could reduce boll nitrogen metabolism intensity, were responsible for the reduced boll development of the conventional Bt cultivar Sikang 1.     

不同基因型棉花品种铃壳重与产量及品质性状的关系

对18个陆地常规非抗虫棉品种铃壳重与7个产量性状、6个纤维品质性状进行了相关性分析与聚类分析。结果表明,铃壳重与全铃重呈极显著正相关,与单铃子棉重、衣指、整齐度指数呈显著正相关,与伸长率呈显著负相关,与皮棉产量、纤维品质综合分值无显著相关。铃壳重较轻与光合产物较多的提供给棉子和纤维的生长发育、促进子棉产量的提高和纤维品质的改善有关。     

Boll size affects the insecticidal protein content in Bacillus thuringiensis (Bt) cotton

Bacillus thuringiensis (Bt) transgenic cotton has been planting in large-scale for more than 10 years in China. It was observed that resistance to bollworm was reduced with the application of big-boll cultivars in China. The objective of the study was to investigate the effects of boll size on the contents of CryIA insecticidal protein in boll shell and cotton seed during the course of boll development. Two experiments were conducted at the Yangzhou University Farm, Yangzhou, China. In 2004, three cultivars including Sikang 1 (small-boll), Xiangza 3 (medium-boll) and Kemian 3 (big-boll) were compared for boll shell volume and 100-seed weight from 10 to 40 days after flowering (DAF), and insecticidal protein contents in boll shell and cotton seed from 10 to 50 DAF. As expected, the differences between cultivars were significant for all the four characteristics. Cultivars with bigger boll shell volume had higher 100-seed weight but lower insecticidal protein contents in both of the boll shell and cotton seed. The correlation between boll size and boll insecticidal protein content was negative (−0.653). The correlation between 100-seed weight and cotton seed insecticidal protein content was significantly negative (−0.645). In 2005, leaf cut (LC) and square removal (SR) treatments were applied to Sikang 1 and Sikang 3. The boll shell volume and 100-seed weight were decreased by LR, but increased by SR. LC significantly enhanced and SR significantly reduced the insecticidal protein contents of boll shell and cotton seed. The correlation between boll size and boll insecticidal protein content (−0.870) and the correlation between 100-seed weight and cotton seed insecticidal protein content were both highly significant and negative (−0.841). Therefore, the results of the study indicated that the boll insecticidal protein content was significantly affected by boll size. The implications of the observed results in breeding, cultural practices and pest management were discussed.     

德州地区棉花常见病虫害诊断与防治方法

为了山东德州地区棉花生产的稳定发展,科学防治病虫害,力求把产量损失降到最低。通过长期的棉花病虫害防治研究与实践,总结出了棉花苗期阶段立枯病、红腐病、棉蚜、棉叶螨等,棉花成株阶段轮纹斑病、棉铃红粉病、棉铃疫病、白霉病、枯萎病、棉铃虫、棉根蚜和棉盲蝽等德州地区常见病虫害的症状、为害特点和防治方法。     

常规棉产量与主要性状的灰色关联度分析

为探索常规棉产量与主要性状的相互关系,以2013年湖北省棉花区域试验19个棉花品种为材料,运用灰色系统理论对影响常规棉产量的12个主要性状进行灰色关联分析。结果表明,主要性状与常规棉产量的关联度大小依次为：籽指（r＝0．491）＞铃期病指（r＝0．430）＞衣指（r＝0．404）＞单株铃数（r＝0．396）＞始果枝着生节位（r＝0．394）＞果枝数（r＝0．390）＞衣分（r＝0．388）＞霜前花率（r＝0．382）＞生育期（r＝0．377）＞单铃重（r＝0．367）＞株高（r＝0．345）。说明在常规棉的选育和高产栽培时,要选择籽指较高、抗病性强的品种,同时注重结铃性和早熟性。     

高产棉花整体棉铃增重途径的研究

以两年度两因子两水平进行高产条件下棉花铃重的形成和分布规律研究表明 ,高产棉花皮棉产量在1975kg·hm-2 以上时整体铃重的提高关键是促进上部各果枝及各果枝 3～ 5节位铃重 ,在氮钾肥与DPC合理运筹下促进中部外围和上部铃在花开 17天后籽棉和纤维量的加快增长 ,提高该部位铃此段时间的发育有利于铃重增加、单铃纤维增多 ,也有利于纤维素的积累 ,提高品质     

棉花不同密度对铃重和衣分的影响

以湘杂棉8号为品种,通过6种不同密度处理试验,研究棉花不同时期不同密度对铃重、铃壳重和衣分的影响。试验表明：棉花单铃重随着密度的增加而逐渐降低,以21000株,hm^2单铃重最高,在同一密度处理中。棉花单铃重：中期〉前期〉后期;棉花的铃壳重随着密度的增加而逐渐降低．在同一密度下,铃壳重都有随着时间的不断推移而逐渐增加的趋势;不同密度处理,各表分差异不显著,在各个处理的不同生长时期。表分率先逐渐增加后降低。