淹水胁迫对丝瓜和苦瓜幼苗形态及不定根解剖结构的影响

Effect of Waterlogging Stress on Morphology and Adventitious Roots Anatomical Structure in Luffa and Balsam Pear Seedlings

以荆州本地丝瓜和香帅5号为试材,研究淹水胁迫对丝瓜和苦瓜幼苗形态、不定根解剖结构和屏障结构的影响。结果表明:丝瓜幼苗淹水胁迫12 d内株高、叶片数及鲜质量与对照差异不显著,淹水胁迫16 d后才显著低于对照,而苦瓜幼苗淹水胁迫4 d后株高、叶片数及鲜质量均显著低于对照。丝瓜幼苗淹水胁迫8 d后淹水部位茎粗(子叶以下1 cm处)显著大于对照,但苦瓜幼苗与对照差异不显著。淹水胁迫16 d后,丝瓜幼苗不定根内有发达的通气组织,而苦瓜没有形成;淹水后丝瓜幼苗不定根幼嫩部位(距根尖20 mm处)出现具明显凯氏带且栓质化的内皮层,而苦瓜幼苗不定根在距根尖40 mm处才出现。说明淹水后丝瓜幼苗不定根内发达的通气组织以及20~40 mm处的屏障结构是丝瓜比苦瓜耐淹水的主要原因。

Taking‘Jingzhoubendisigua’and‘Xiangshuai No.5’as experimental material,this paper studied the effect of waterlogging stress on the morphology of luffa and balsam pear seedlings,adventitious root anatomical structure and barrier structure.The results showed that the plant height,number of leaves and fresh weight of luffa seedling were not significantly different with that of the contrast under waterlogging stress for 12 days.Only after 16 days,those figures were remarkably lower than that of the contrast.But the plant height,number of leaves and fresh weight of balsam pear seedling were significantly lower than that of the contrast under waterlogging stress for 4 days.The diameter of flooding stem(cotyledons below 1 cm)of luffa seedlings was significantly thicker than that of the contrast after under waterlogging stress for 8 days.While,there was no significant differences between balsam pear seedlings and the contrast.After under waterlogging stress for 16 days,there were well developed aerenchyma in adventitious roots of luffa seedlings,but balsam pear seedlings had not formed aerenchyma yet.After flooding,the endodermis(at 20 mm)of luffa seedlings adventitious roots appeared inner barrier structure,while that of balsam pear seedlings appeared higher at 40 mm.This indicated that the main reason for luffa seedlings more tolerant to waterlogging than balsam pear seedlings was the developed aerenchyma and the inner barrier structure at 20-40 mm in adventitious roots of luffa seedlings.