钾高效基因型棉花的筛选及其生理机制的研究

通过营养液培养,设缺K和适K处理,进行棉花苗期培养,以苗期干物质的K效率系数(-K/ K)评价K效率差异,从86个不同系谱的棉花品种中分次逐步筛选,获得4个候选品种.对候选品种进行全生育期土培试验,设施K和不施K处理,获得皮棉产量,以皮棉产量的K效率系数(-K/ K)来反映品种间的K效率差异,确定103为K高效高潜力基因型,122为K低效低潜力基因型,163和165为K高效低潜力基因型.103具有较强的吸收土壤速效K、活化土壤缓效K的能力,并以较低的K含量往繁殖器官运输分配,建成较多的子棉和皮棉,这可能是其K高效的机制之一.

On the Screening High Potassium Efficiency Cotton Genotypes and Its Mechanisms

Based on method of "two step selection" from 86 cotton (Gossypium hirsutum L.) cultivars from 2001 to 2003, an experiment was conducted to study potassium (K) efficiency of varied cotton genotypes through solution and soil pot culture. The result showed that K efficiency coefficients (KEC: K efficiency coefficients is the rate of low K level plant weight to high K level plant weight at seeding stage, or K efficiency coefficients is the rate of low K level cotton fiber yield to high K level cotton fiber yield during whole stage) existed prominent difference between various genotypes. The range of KEC was from 0.08 to 0.28 at seeding stage. According to agricultural character, KEC and different cotton pedigrees, 6 representative cultivars were selected for further experiment, and after raising low K level selection on these 6 cultivars, 4 typical cultivars were selected for whole growth stage experiment. Together with other indices, such as agricultural characters, fiber yields, yield potential and so on, cotton fiber yield and KEC (range from 0.24 to 0.39) were used to identify the real K high efficiency genotype. Finally 103 was regarded as the K high efficiency and high yield potential genotype, 122 as the K low efficiency and low yield potential genotype, 163 and 165 as the K high efficiency and low yield potential genotypes. 103 could get much more yield with low K content at the same K level, so it had stronger ability to make full use of plant potassium than other genotypes. Besides, 103 could absorb much soil rapidly available potassium and activate soil slowly available potassium, so 103 had higher absorption and utilization abilities to soil potassium, all of these maybe explain why 103 was the K high efficiency and high yield potential genotype.