SENSITIVITY CYCLING AND MECHANISM OF PHYSICAL DORMANCY BREAK IN SEEDS OF IPOMOEA HEDERACEA (CONVOLVULACEAE)
SENSITIVITY CYCLING AND MECHANISM OF PHYSICAL DORMANCY BREAK IN SEEDS OF IPOMOEA HEDERACEA (CONVOLVULACEAE)
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DOI：
10.1086/597270
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发表时间：
2009-05-01
影响因子：
2.3
通讯作者：
Baskin, Carol C.
中科院分区：
文献类型：
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作者：
Jayasuriya, K. M. G. Gehan;Baskin, Jerry M.;Baskin, Carol C.
种子对物理休眠（PY）打破的敏感性循环发生在一些豆科和旋花科植物中。旋花科和其他一些被子植物科物种种子中的PY可以通过干燥储存来破坏。然而，在干藏过程中打开种皮中的水隙（休眠打破）的机制尚未研究。在这里报道的研究中，我们确定了是否敏感性循环发生在Ipomoea hederacea（旋花科）的种子，并研究了干燥储存对水隙开放的影响。种子可以在对打破休眠不敏感和敏感的状态之间循环，敏感种子的休眠可以通过在高温至中等温度下干燥储存来打破。种脐下部被堵塞的种子在贮藏过程中损失的水分最少。失水率与休眠解除率呈显著正相关。在干燥储存过程中，水通过肺门裂隙解吸降低了隆起（水隙）下方的蒸汽压，这导致隆起周围形成狭缝（水隙开口）。不敏感种子的水解吸量低，因为种门裂隙保持关闭，因此水隙没有打开。
Sensitivity cycling to physical dormancy (PY) break in seeds is known to occur in some Fabaceae and Convolvulaceae species. PY in seeds of species of Convolvulaceae and of some other angiosperm plant families can be broken by storing them dry. However, the mechanism of opening the water gap in the seed coat (dormancy break) during dry storage has not been investigated. In research reported here, we determined whether sensitivity cycling occurs in seeds of Ipomoea hederacea (Convolvulaceae) and investigated the effect of dry storage on opening of the water gap. Seeds can cycle between insensitive and sensitive states to dormancy break, and dormancy can be broken in sensitive seeds by storing them dry at high to moderate temperatures. Seeds with the lower part of the hilum blocked lost a minimal amount of water during storage. Percentage water loss was significantly correlated with percentage dormancy break. Desorption of water through the hilar fissure during dry storage reduced the vapor pressure below the bulges (water gap), which caused slits to form around the bulges (opening of water gap). The amount of water desorption was low in insensitive seeds because the hilar fissure remained closed and thus the water gap did not open.