不同钾效率棉花基因型对低钾胁迫的反应

Response of Difference Potassium Efficiency Cotton Genotypes to Potassium Deficiency

采用盆栽试验,对通过苗期筛选获得的4个(103、122、163、165)钾效率不同的棉花基因型进行全生育期试验,主要研究在不施钾(K2O 0 g.kg-1)与施钾(K2O 0.80 g.kg-1)条件下各部位钾含量、农艺性状、产量和纤维品质的反应。高效高潜基因型103结桃数最多,而脱落率最低;它的衣分高而子指较低,说明其能把较多养分转移到皮棉,以获得较高的经济产量;其单株皮棉产量在缺钾和施钾条件下分别是低效低潜基因型122的2.57倍和1.83倍;低效低潜基因型122的脱落率在各个时期均最高,结桃数最少,单铃重、子指、单株皮棉产量都是最小。103各个部位钾含量较低,122的钾含量则较高,说明103以较低的钾含量即能维持其正常的生长,这或许是其钾高效的因素之一;施钾显著提高了各个基因型的纤维整齐度、比强度、纤维长度和麦克隆值,但降低了伸长率;103衣分最高,纤维长度、整齐度、比强度、伸长率中等,麦克隆值施钾和缺钾分别是A1和C2级。122纤维长度为最高,衣分、整齐度、比强度中等,其伸长率最低,麦克隆值B1级。高效低潜基因型163、165的产量和纤维品质等表现中低水平。

Based on selection from 86 cotton （Gossypium hirsutum L. ） cultivars in 2002 and 2003, four different potassium （K） efficiency cotton genotypes（code. 103、122、163、165） had been gotten. This experiment was conducted to study potassium （K） efficiency and physiological mechanism of these four genotypes through soil pot culture in 2003, and this test was from April 20 to October 9. Which installed two K levels（-K, K2O 0 g·kg^-1 and ＋K, K2O 0.80 g·kg^-1） ,each level had five repetitions, cotton seeds were dipped into 50-60℃ water for 30 minutes, then were placed at normal temperature. When they germinated, and were seeded in the soil pots, and each pot remained one individual cotton plant finally. The experiment carried out at Huazhong Agricultural University experiment station. During the course of growth, much attention had been paid to deal with plant disease and insect. The agricultural character changes of these four genotypes had been recorded, which included the plant boll numbers, total nods, the number of sympodia, and so on. After boll split five or seven days, the seed cotton had been picked up, then weighted, basked and roiled, finally got lint yield and analyzed fiber quality. At the end, the plant root, stem and leaf harvested apart, and placed into oven at 105℃ for 30 minutes, dried at 70℃ for 24 hours, finally, ground the dried samples. The fiber quality was tested by HVICC in Supervision Inspection and Test Center of Cotton Quality, Ministry of Agriculture, China. The fiber length, length uniformity, strength, elongation and micronaire value were tested. The result showed that K efficiency existed prominent difference between varied genotypes. High K efficiency and high yield potentiality genotype 103 grew much better than other genotypes, it got the largest boll numbers, the lowest rate of boll shed and the highest lint yield. The lint yield of genotype 103 was that of 1.83, 1.87 and 1.74 times to 122, 163 and 165 genotypes at ＋K treatment; and at -K condition, the lint yield of genotype 103 was that of 2.57, 2.08 and 1.51 times to 122, 163 and 165 genotypes. Low K efficiency and low yield potentiality genotype 122 appeared very badly, not only growth was poor, but also its ability of absorption and utilization K was weak. Different parts of 103 hadthe lowest K contents, but 122 had the highest, so 103 could grow much better and get highest yield in low K content conditions, which maybe one of a factor that 103 was high K-efficiency genotype. Potassium could increase fiber length uniformity, elongation and micronaire. Different K efficiency genotype also appeared difference on fiber quality characters, at the same K level, genotype 103 had the highest lint percent age and middle in fiber length, length uniformity, strength, elongation and micronaire, and genotype 122 had the highest fiber length, micronaire and middle in lint percent, length uniformity, strength, its elongation was the lowest. Generally, different cotton genotypes fiber quality characters were worse at -K than that of ＋K, but this difference was not so distinctness as lint yield.