棉花耐低钾基因型筛选条件和指标的研究  

Conditions and Indicators for Screening Cotton(Gossypium hirsutum) Genotypes Tolerant to Low-Potassium

作　　者：田晓莉[1] 王刚卫[1] 朱睿[1] 杨培珠[1] 段留生[1] 李召虎[1] 

机构地区：[1]中国农业大学作物化学控制研究中心/农业部作物栽培与耕作学重点开放实验室/植物生理学与生物化学国家重点实验室,北京100193

出　　处：《作物学报》2008年第8期1435-1443,共9页Acta Agronomica Sinica

基　　金：国家自然科学基金项目(30100111;30571118)

摘　　要：以2004年我国棉区的主栽品种/组合/品系为主,收集50个基因型,在苗期室内液培条件下(低钾浓度和高钾浓度分别为0.02mmolL-1和2.50mmolL-1)对棉花耐低钾基因型的适宜筛选苗龄和评价指标进行研究,并与田间缺钾土壤(速效钾含量为59.88mgkg-1)的筛选结果进行比较。结果表明,棉花5叶期幼苗基因型间生物量的变异系数明显高于3叶期,适宜进行耐低钾基因型筛选。低钾条件下的绝对生物量与相对生物量(0.02/2.50)、吸钾量和钾利用指数(KUI,单位浓度钾所形成的生物量)极显著(P<0.01)相关,相关系数分别为0.7690、0.9522和0.9791。根长、根表面积与整株吸钾量的相关系数分别为0.5201(P<0.01)和0.3325(P<0.05)。子叶缺钾斑占子叶总面积的比例(S)在基因型间变化幅度大(变异系数为44.46%)、符合正态分布、与生物量极显著相关(r=–0.4455,P<0.01),可作为棉花苗期耐低钾基因型筛选的辅助指标。种子含钾量与棉花幼苗子叶的S值、生物量、钾吸收量和KUI均无相关关系。液培条件下5叶期幼苗的整株生物量与田间条件下产量器官干重极显著相关(r=0.5091,P<0.01),证明苗期室内液培筛选具有可行性,可作为对大量基因型的初筛方法,典型基因型需要在田间进行复筛。Commercial cotton production is currently limited by varying levels of potassium （K） deficiency. Screening for low-potassium tolerant cotton genotypes is necessary to alleviate the shortage of available potassium in soil. However, there is no standard procedure for such screening. Fifty cotton genotypes, mainly predominant cultivars/lines developed in 2004 in China, were tested under a hydroponic culture at low （0.02 mmol L^-1） and adequate （2.50 mmol L^-1） K levels. We determined genotypic differences in dry matter and associated traits at the seedling stage and compared with dry weight of reproductive organs （squares, flowers and uncracked and cracked bolls） in a field with potassium-deficient soil （59.88 mg kg^-1）. Coefficient of variation （CV） among genotypes for whole plant dry weight increased from 15.13% at 1-leaf stage to 21.13% and 28.58% at 3- and 5-leaf stages, suggesting that differences among genotypes would manifest more clearly as seedlings aged. Together with the rather short growing period （about 20 d）, we considered the 5-leaf stage most suitable for the screening at the seedling stage. The relative dry weight （RDW） of the whole plant （0.02/2.50） correlated well （r = 0.7690, P 〈 0.01） with absolute dry weight （ADW） in the low K medium, but it had a higher CV than the latter （up to 37.39% at the 5-leaf stage）. This suggests that the RDW would be a better screening index than ADW. Under the K-deficient media, highly significant positive correlations were observed between K accumulation and dry matter （r = 0.9522）, K utilization index （KUI, dry matter produced per 1‰ K） and dry matter （r = 0.9791）, respectively. This shows that cotton tolerance to low K is a function of uptake and utilization. Correlation coefficients between root length and K accumulation, root surface area and K accumulation were 0.5201 （P 〈 0.01） and 0.3325 （P 〈 0.05）, respectively. The ratio of spotted area caused by potassium deficiency to total cotyle

关 键 词：棉花 基因型 耐低钾 筛选 

分 类 号：S562[农业科学—作物学]