ISOLATION OF TOMATO STRAINS VARYING IN POTASSIUM ACQUISITION USING A SAND-ZEOLITE CULTURE SYSTEM
ISOLATION OF TOMATO STRAINS VARYING IN POTASSIUM ACQUISITION USING A SAND-ZEOLITE CULTURE SYSTEM
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DOI：
10.1007/bf00017676
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发表时间：
1995-09-01
期刊：
影响因子：
4.9
通讯作者：
GABELMAN, WH
中科院分区：
文献类型：
--
作者：
CHEN, JJ;GABELMAN, WH
在砂沸石培养基中，对100个番茄品系在低钾(0.25 mm)和适钾(1.0 mm)下的反应进行了评估，这些菌株代表了不同的地理区域。不同类型的菌株可分为三种类型：(1)高效菌株，其特征是在低钾胁迫下获得钾的能力和干物质积累与在充足钾供应下生长的菌株相当；(2)在充足钾供应下生长良好但在低钾胁迫下获得钾的能力较低的低效菌株，相应地，干重产量较低；(3)生长缓慢的菌株，其组织中钾含量低，干物质积累低，与外部钾水平无关。这些高效且生长缓慢的菌株大多来自南美洲和中美洲，那里是番茄起源和驯化的地方。然而，来自其他地区的菌株在获得钾方面大多表现出低效。与钾获取效率相关的两个明显特征被识别出来。一种是低钾胁迫下根长的增殖，另一种是单位根长的高净钾内流速率。我们的结果表明，植物在栽培过程中失去了有效获取养分的机制，植物起源和驯化中心蕴藏着宝贵的遗传资源，有助于提高植物获取养分的效率。
One hundred tomato strains, representing widely diverse geographic areas, were evaluated in a sand-zeolite culture medium for their response to both low (0.25 mM) and adequate (1.0 mM) K levels. Three types of strains differing in K acquisition were classified: (1) efficient strains characterized by their ability to acquire K under low-K stress and with dry matter accumulation comparable to the strains grown under adequate-K supply, (2) inefficient strains that grew well under adequate-K supply but with a low capacity to acquire K at low-K stress and correspondingly lesser dry weight production, and (3) slowly growing strains featured by low K content in tissue and low dry matter accumulation irrespective of external K levels. The efficient and slowly growing strains came mostly from South and Central America, where tomato originated and was domesticated. Strains from other regions, however, mostly showed inefficiency in K acquisition. Two distinct features associated with the efficiency of K acquisition were identified. One was the proliferation of root length and another was high net K-influx rates per unit root length under low-K stress. Our results suggested that mechanisms for efficient acquisition of nutrients were lost during the cultivation of plants, and centers of plant origin and domestication contain valuable genetic resources for improving plant efficiency in nutrient acquisition.