Genotypic Variation in Biomass Production at the Early Vegetative Stage among Rice Cultivars Subjected to Deficient Soil Moisture Regimes and Its Association with Water Uptake Capacity
Genotypic Variation in Biomass Production at the Early Vegetative Stage among Rice Cultivars Subjected to Deficient Soil Moisture Regimes and Its Association with Water Uptake Capacity
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DOI：
10.1626/pps.15.82
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发表时间：
2012-04-01
影响因子：
2.5
通讯作者：
Kokubun, Makie
中科院分区：
文献类型：
--
作者：
Matsunami, Maya;Matsunami, Toshinori;Kokubun, Makie
水稻品种的吸水能力和水分利用效率（WUE）的遗传改良是在水分有限条件下提高生产力的一种选择。我们研究了70个水稻品种（69个品种的NIAS全球水稻核心收集和Azucena）在不同土壤水分条件下的生物量生产的基因型差异，并确定是否吸水能力或WUE的变化，如果有的话。将两周龄的幼苗移植到盆中，并在三种土壤水分状况下在环境调节的生长室中生长三周：淹水（-0.02MPa土壤水势）和两种未淹水（-0.10和-0.52MPa）条件。在所有三个制度下，观察到大量的基因型变异的总干重（TDW）。在所有供试品种中，TDW与吸水能力呈极显著相关，而与WUE不相关。然而，几个品种表现出较高的水分利用效率，同时表现出优越的上级生物量生产下-0.52 MPa的制度。无论水分状况如何，品种间的吸水量与根干重显著相关，而单位根干重的吸水量存在显著的基因型差异。这些结果表明，一个显着的基因型差异存在于生物量生产在早期营养生长在水分亏缺条件下，这种差异似乎主要归因于更大的吸水能力，此外，在耐旱品种较高的WUE。
Genetic improvement in water uptake ability and/or water use efficiency (WUE) of rice cultivars is one option to enhance productivity under water-limited conditions. We examined the genotypic variation in biomass production among 70 rice cultivars (69 cultivars of NIAS global rice core collection and Azucena) under different soil moisture conditions, and to identify whether water uptake ability or WUE is responsible for the variation, if any. Two-week-old seedlings were transplanted into pots and grown for three weeks in an environmentally-regulated growth chamber under three soil moisture regimes: flooded (-0.02 MPa soil water potential) and two unflooded (-0.10 and -0.52 MPa) conditions. Substantial genotypic variations in total dry weight (TDW) were observed under all three regimes. Among all the cultivars tested, TDW was significantly correlated with water uptake ability, but not with WUE. However, several cultivars exhibited comparably higher WUE while showing superior biomass production under the -0.52 MPa regime. The amount of water uptake was significantly correlated with root dry weight among cultivars regardless of moisture regimes, while substantial genotypic difference in the amount of water uptake per unit root dry weight was observed. These results indicate that a marked genotypic difference exists in biomass production at the early vegetative growth under water-deficient conditions, and that this difference appears to be ascribed primarily to greater water uptake capacity, and additionally to higher WUE in drought-tolerant cultivars.