A shoot based Na+ tolerance mechanism observed in pumpkin-An important consideration for screening salt tolerant rootstocks
A shoot based Na+ tolerance mechanism observed in pumpkin-An important consideration for screening salt tolerant rootstocks
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DOI：
10.1016/j.scienta.2017.02.020
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发表时间：
2017-04-14
影响因子：
4.3
通讯作者：
Bie, Zhilong
中科院分区：
文献类型：
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作者：
Niu, Mengliang;Xie, Junjun;Bie, Zhilong
以28个南瓜砧木和16个自交系为材料，研究了盐胁迫下南瓜离子积累和生长的变化。7个形态性状和3个离子性状的变异和相关均达到显著水平。根据3个关键性状将44个基因型分为3类，即耐盐型（地上部Na+浓度低、盐害指数低、相对地上部干重高）、敏感型（地上部Na+浓度高、盐害指数高、相对地上部干重低）和中间型（地上部Na+浓度高、盐害指数低、相对地上部干重高）。测定了幼苗根、茎、叶脉和叶肉四个部位的Na+浓度。结果表明，不同南瓜类群表现出不同的Na+分配模式，耐性组限制Na+在根部，中间组限制Na+在茎和叶脉，敏感组向叶肉组织转运较多的Na+。从3组材料中选取6个基因型作为砧木，与盐敏感型黄瓜接穗嫁接，以评价嫁接组合的耐盐性。结果表明，嫁接在耐盐南瓜上的黄瓜地上部Na+浓度显著低于敏感南瓜和中间南瓜。而敏感南瓜嫁接黄瓜与中间南瓜嫁接黄瓜之间的差异不显著。这些研究结果表明，除了根中的Na+限制，在地上部的替代机制可能通过一些南瓜基因型，如果这些基因型被用作砧木，他们不能表现以及在自根条件下，他们的芽已被黄瓜接穗取代。我们的发现提供了一个深入了解耐盐砧木的筛选。(C)2017爱思唯尔B.V.保留所有权利。
Ion accumulation and growth of 28 commercial pumpkin rootstocks and 16 inbred lines were investigated under saline conditions. Significant variation and correlations were observed in seven morphological traits and three ionic traits. 44 genotypes were clustered into three groups, namely, tolerant (low Na+ concentration in the shoot, low salt injury index, and high relative shoot dry weight), sensitive (high Na+ concentration in the shoot, high salt injury index, and low relative shoot dry weight) and intermediate (high Na+ concentration in shoot, low salt injury index, and high relative shoot dry weight) by three key traits. Na+ concentration in four parts of seedlings (root, stem, leaf veins, and mesophyll) were determined. Results indicated that different pumpkins groups show various Na+ distribution patterns (tolerant group restricted Na+ in roots, intermediate group restricts Na+ in their stems and leaf veins and sensitive group transported more Na+ to mesophyll tissues). Six genotypes were selected from three groups as rootstocks and grafted with a salt sensitive cucumber scion for evaluation the salt tolerance in grafting combinations. Results showed that Na+ concentration in the shoot of cucumbers grafted onto tolerant pumpkins was significantly lower than onto the sensitive and intermediate pumpkins. However, no significant differences were observed between the cucumbers grafted onto sensitive and intermediate group of pumpkins. These findings indicate that beside Na+ restriction in root, an alternative mechanism in shoot may be adopted by some pumpkin genotypes; if those genotypes are used as rootstocks they cannot perform as well as in self-root condition for their shoots have be replaced with cucumber scions. Our finding provides an insight into the screening of rootstocks tolerant to salinity. (C) 2017 Elsevier B.V. All rights reserved.