干旱绿洲农田盐渍化对大麦和苜蓿干物质分配的影响

为探讨不同盐渍化梯度下大麦和苜蓿干物质积累和分配的特征与其耐盐机理的关系,采用大田试验的方法,通过一个生长季的观测,研究了不同盐渍化梯度下大麦和苜蓿干物质的积累和分配特征.以非盐渍化大麦地和苜蓿地作为对照,在作物生长季内,不同盐渍化梯度大麦和苜蓿茎、叶、根及其他生殖器官的干物质积累和分配特征有所不同.1)在农艺性状上,盐渍化对大麦的茎秆生长和繁殖器官的生长发育有显著影响,其千粒重、单株穗粒数和株高的G/CK变幅分别在80.37％～39.44％、87.95％～45.27％和95.10％～50.70％之间.对苜蓿的茎生长有显著影响,其株高和主、侧茎长的G/CK变幅分别在69.20％～27.60％、70.80％～30.30％和66.00％～16.50％之间；2)在干物质在各器官的积累与分配上,与CK比,不同盐渍化梯度下大麦和苜蓿的干物质更多的分配在叶和根上,而向茎的干物质分配比率逐渐减少；在整个生长季,随着盐渍化梯度的增加,大麦和苜蓿各生育期干物质的增长分配中心滞后于CK中的作物；3)在地上部分配比率和根冠比上,随盐渍化梯度的增加,大麦和苜蓿地上部的分配比率降低,而根冠比提高.在盐渍化过程中,大麦和苜蓿通过将干物质更多的转移到根和叶器官上,同时减少干物质向茎秆的分配比率以及降低地上部的分配比率和提高根冠比的途径来适应盐胁迫.

Influence of salinization on dry matter partitioning of Medicagosativa and Hordeum vulgare in arid oasis

The research was aimed to clarify the relationship between traits of dry matter accumulation and distribution of alfalfa and barley and salt-tolerant mechanism.The traits of dry matter accumulation and distribution of alfalfa and barley in different salinization gradients were studied at one-growing-season under field conditions.A non-salinized plot was used as the control.There were evident differences in the traits of dry matter accumulation and distribution of tissues in alfalfa and barley from the different salinization gradients.1) In agronomic traits,salinization had significant impacts on stem and ear of barley.The change range of G/CK in dry weight of grains per plant,number of grains per ear and plant height were 80.37%-39.44%,87.95%-45.27% and 95.10%-50.70% respectively.However,alfalfa stem was most sensitive to increasing salt stress.The change range of G/CK in plant height and length of main branch and secondary branch was 69.20%-27.60%,70.80%-30.30% and 66.00%-16.50% respectively.2) In dry matter accumulation and distribution,salinization resulted in more distribution of dry matter in root and leavethan stem.The accumulation center of dry matter in two plants was slower in salinization gradients than the CK plant at any growth stage.3) The dry matter distribution ratio of above-ground decreased with salinization gradients,but increasing in root/shoot ratio for both alfalfa and barley.It is evident that both alfalfa and barley adapted to salt stress by distributing more dry matter in root and leave but not in the stem.