Root penetration of strong soil in rainfed lowland rice: comparison of laboratory screens with field performance
Root penetration of strong soil in rainfed lowland rice: comparison of laboratory screens with field performance
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DOI：
10.1016/s0378-4290(02)00039-4
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发表时间：
2002-07-01
影响因子：
5.8
通讯作者：
Wade, LJ
中科院分区：
文献类型：
--
作者：
Clark, LJ;Cope, RE;Wade, LJ
具有较好硬盘穿透性的水稻CVS有望在降雨较少的低地获得更强的抗旱性。虽然已经描述了促进鉴定或培育具有良好根渗透能力的CVS的实验室方法，但仍有必要根据田间表现来验证这种筛选。在这里，我们比较了八个CVS(IR20，CT9993，KDML 105，IR58821，NSG19，IR62266，Mahsuri和IR52561)的现场测量和实验室筛选测量。这些都是用淹没的蜡层筛子进行筛选的(为了进行比较，还包括Moroberekan，SG329和IR36)。在8个品种中，IR58821对60%蜡层的穿透效果最好，平均每株根轴穿透5.8根。表现最差的是IR52561，平均每株株轴0.6个。CVS IR20、CT9993、KDML 105、IR58821也使用(未淹没的)砂岩筛网进行了筛选(与Azucena、Bala、Moroberekan、Kinandang Patong和IR36一起进行比较)。砂芯筛网允许整个砂芯的机械阻抗独立于曝气和水状况而变化。高阻抗处理是通过在砂芯上放置重量来获得的，这极大地抑制了根的生长，尽管砂芯屏蔽中CVS对阻抗的响应差异很小。水稻根系穿透蜡层的能力似乎与其穿过坚硬的沙子时的伸长无关，而是与它们在遇到蜡层时抵抗屈曲的能力有关。与现场测量结果对比表明，尽管IR58821在现场表现最好，但在蜡层筛选中表现良好的CVS在现场并不一定具有良好的硬质渗透性能。结论是，需要进一步的工作来比较田间根部渗透率与实验室筛选的根部渗透率。(C)2002 Elsevier Science B.V.保留所有权利。
Rice cvs with better hardpan penetration would be expected to be more drought resistant in the rainfed lowlands. Although laboratory methods to facilitate the identification or breeding of cvs with good root-penetration ability have been described, there is a need to validate such screens against field performance. Here, we compare previous field measurements with laboratory screening measurements in eight cvs (IR20, CT9993, KDML 105, IR58821, NSG 19, IR62266, Mahsuri and IR52561). These were screened (together with Moroberekan, SG329 and IR36 for comparative purposes) using a flooded wax-layer screen. Of the eight cvs, IR58821 gave the best penetration of a 60% wax layer, with a mean penetration of 5.8 root axes per plant. The worst performer was IR52561, with a mean of 0.6 axes per plant. The cvs IR20, CT9993, KDML 105, IR58821 were also screened (together with Azucena, Bala, Moroberekan, Kinandang Patong and IR36 for comparative purposes) using a (non-flooded) sandcore screen. The sand-core screen allowed mechanical impedance of the whole sand core to be varied independently of aeration and water status. High impedance treatments were obtained by placing weights on the sand cores, which greatly decreased root growth, although differences between cvs in response to impedance in the sand-core screen were small. The ability of rice roots to penetrate wax layers did not appear to be related to their elongation through strong sand, but rather to their ability to resist buckling on encountering the wax layer. Comparison with field measurements showed that cvs with good performance in the wax-layer screen did not necessarily have good hardpan penetration in the field, although IR58821 was the best performer in the field. It is concluded that further work is required to compare root penetration in the field with root penetration in laboratory screens. (C) 2002 Elsevier Science B.V. All rights reserved.