作物相对耐盐性的研究Ⅰ．大麦和小麦不同生育期的耐盐性

STUDIES ON RELATIVE SALF TOLERANCE OF CROPS I. SALT TOLERANCE OF BARLEY AND WHEAT AT DIFFERENT GROWTH STAGES

本文通过盆栽生物试验和室内培养试验，对大麦和小麦两种作物不同生长发育阶段的耐盐性进行了研究。结果表明，两种作物均在萌芽期、苗期和拔节孕穗期对土壤盐分最敏感。随土壤盐度增加，作物对钠的摄取量剧增，对钾的摄取量明显减少，对钙的摄取量在苗期和拔节孕穗期也有一定程度减少。此外，随土壤盐度增加，作物叶中Ｃａ／Ｎａ比和Ｋ／Ｎａ比均降低，其中尤以Ｋ／Ｎａ比的降低最显著，表明盐分胁迫下作物吸钠对钾吸收的影响最大。本文还就盐分敏感期作物易受盐分胁迫的可能机制进行了探讨。

Excessive salt in salt-affected soil affects the growth and development of crops.Although soil salinity affects the growth and development of crops at all the growthstagee, the salt-sensitiveness of some crops differ remarkably at various stages. To-lerance to salinityis not a fixed property of a apecies but varies with the growthstages of the crop.A pot culture experiment was conducted to determine salt tolerance of barleyand wheat at various growth stages. The soils tested were salinized at various sta-ges with distilled water containing salt at four levels. After salinized,the osmoticpotential of soil solution increased by 0, -0.4, -0.8 and -1.6MPa, respectively.The results showed that both barley and wheat were sensitive to salt at the ger-mination stage, seedling stage, and jointing and booting stage, Plant element analy-sis indicated that sodium absorption of barley and wheat increased sharply, potassiumabsorption decreased remarkably, and calciuin absorption decreased slightly with theincrease of soil salinity. Leaf element analysis indicated that K￣ +/Na￣+ ratios andCa￣(2+)/Na￣+ ratios in the leaves decreased during the whole growth and developmentperiod with the increase of salinity level in the medium. The mechanisms of saltstress at the salt-sensitive stages, ie. the germination stage, seedling stage, and join-ting and booting stage, were also discussed in this paper. The mechanisms of saltstress can be attributed to water stress caused by soil salinity and ion stress.