盐碱胁迫对甜瓜种子萌发及幼苗生长发育的影响

【目的】分析种子萌发和幼苗发育两个阶段不同水平盐胁迫处理对甜瓜生长的影响,为甜瓜耐盐资源筛选提供理论依据。【方法】以4个甜瓜品种为材料,设置3个处理浓度,分别在种子萌发期和幼苗期进行盐胁迫处理,研究不同浓度盐处理对甜瓜种子萌发、幼苗生长发育及根系形态特征的影响。【结果】4个甜瓜品种在低盐处理下可以维持50%以上的发芽率和60%以上的发芽势,但高盐胁迫下的发芽势和发芽率均呈现显著下降。各甜瓜品种萌发指标综合表现为网纹香>风味5号>西州密17号>黄皮9818。在150 mmol/L盐浓度时,黄皮9818受到的抑制影响比较明显,萌发速度较CK延长了49.8%。各甜瓜品种株高、茎粗、地上/下生物量积累随盐胁迫浓度的上升总体呈下降趋势,且与高盐浓度呈显著负相关,但相同浓度处理下网纹香受到的抑制作最小。盐胁迫均使4种甜瓜的根冠比随浓度的增加呈现先降低再上升的趋势,且高盐浓度下明显高于CK。各甜瓜盐敏感指数和耐受性指数均下降,特别是耐受性指数在浓度为100 mmol/L下降相对明显,4个甜瓜品种在高浓度盐胁迫的敏感性升高,其盐分耐受性降低。盐胁迫下4个甜瓜的根系形态学参数变化基本一致,均呈下降趋势,并且与CK相比差异显著。【结论】盐胁迫下网纹香在种子萌发期和幼苗生长期中的综合表现均优于其它3个品种,网纹香适应在新疆盐碱土壤条件下生长。

Effects of Saline-alkali Stress on Seed Germination and Seedling Growth of Muskmelon

【Objective】 To analyze the effects of different levels of salt stress on the growth of muskmelon from two stages of seed germination and seedling development, and to provide theoretical basis for the screening of salt-tolerant resources of muskmelon. 【Method】 Four muskmelon varieties were used as experimental research materials, three treatment concentrations were set, and salt stress treatment was carried out at seed germination stage and seedling stage, respectively, to study the effects of different concentration of salt treatment on seed germination, seedling growth and root morphological characteristics. 【Results】 The germination rate and germination potential of the four melon varieties under low salt stress could maintain more than 50% and 60%, but the germination potential and germination rate under high salt stress showed significant decrease.The comprehensive germination index of melon varieties was reticulated Wangwenxiang>Fengwei5>Xizhoumi 17>Huangpi 9818. At 150 mmol/L salt concentration, Huangpi 9818 was significantly inhibited, and its germination rate was 49.8% longer than that of CK. Plant height, stem diameter and aboveground/below biomass accumulation of all melon varieties showed a decreasing trend with the increase of salt stress concentration, and had a significant negative correlation with high salt concentration. However, the inhibition of Wangwenxiang was the least under the same concentration treatment.Under salt stress, the root-shoot ratio of the four kinds of muskmelon showed a trend of decreasing first and then increasing with the increase of concentration, and it was significantly higher than that of CK under high salt concentration. The salt sensitivity index and tolerance index of each melon decreased, especially the tolerance index decreased significantly when the concentration was 100 mmol·L^-1, indicating that the sensitivity of the four melon varieties to high salt stress increased, and their salt tolerance decreased.Under salt stress, the root morphological parameters of four kinds of muskmelon were basically the same, all showed a downward trend, and the difference was significant compared with that of CK. 【Conclusion】 The comprehensive performance of Wangwenxiang was better than the other three varieties in the seed germination and seedling growth stages under salt stress, and showed better tolerance to salt environment. Therefore, Wangwenxiang could be used as an alternative salt tolerant germplasm resource.