The ability of wheat cultivars to withstand drought in UK conditions: formation of grain yield
The ability of wheat cultivars to withstand drought in UK conditions: formation of grain yield
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DOI：
10.1017/s0021859601001836
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发表时间：
2002-03-01
影响因子：
2
通讯作者：
Sylvester-Bradley, R
中科院分区：
文献类型：
--
作者：
Foulkes, MJ;Scott, RK;Sylvester-Bradley, R
1993/94年、1994/95年和1995/96年三个干旱年份，在英国ADAS glleadthorpe的一个中等沙地上，试验了6个冬小麦品种对灌溉干物质生长、整个季节干物质向叶、茎和穗的分配以及最终收获时对籽粒的反应。选择Haven、Maris Huntsman、Mercia、Rialto、Riband和Soissons进行花期和茎部可溶性碳水化合物的对比研究。土壤水分最大亏缺量（SMD）历年均超过140 mm，其中1994年6月初和1995年、1996年5月亏缺量最大（约75 mm）。干旱对生物量分配的影响主要表现为：开花前叶片比例下降，灌浆前半期茎储备向籽粒的再分配提前。限制水分供应使粮食产量在1994年下降1.83 t/ha (P < 0.05)，随着干旱时间的延长，1995年下降3.06 t/ha (P < 0.001)， 1996年下降4.55 t/ha （P < 0.001）。平均3年，6个品种的产量响应差异显著（P < 0.05）。Rialto和Mercia的损失仅为2.8吨/公顷，而Riband和Haven的损失为3.5吨/公顷。苏瓦松和亨茨曼的损失中等。在干旱持续时间较长的2年中，Haven的平均生物量下降幅度（6.0 t/ha）大于Maris Huntsman (4.2 t/ha) （P < 0.05）。因此，Haven的粮食产量对干旱的敏感性部分源于生物质生长对干旱的敏感性。6个品种的收获指数（收获时籽粒与地上部干物质之比）对灌溉的响应也存在差异（P < 0.05），并对产量响应有贡献。在水分有效度受限的6个品种中，Rialto的HI降幅最小（- 0.033）；这部分解释了该品种的抗旱性。降幅最大的是马里斯·亨茨曼（-0.072）。不同品种的花期差异可达9天，但这与灌溉对粮食产量的响应相关性较差。未灌水作物开花时茎可溶性碳水化合物在220 ~ 300 g/m(2)之间变化；更大的积累似乎与干旱下更好地维持HI有关。结论是，高茎可溶性碳水化合物储备可以用来提高英国温带气候的抗旱性，但早开花似乎不太可能有用。
Experiments in three dry years, 1993/94, 1994/95 and 1995/96, on a medium sand at ADAS Gleadthorpe, England, tested responses of six winter wheat cultivars to irrigation of dry-matter growth, partitioning of dry matter to leaf, stem and ear throughout the season, and to grain at final harvest. Cultivars (Haven, Maris Huntsman, Mercia, Rialto, Riband and Soissons) were selected for contrasts in flowering date and stem soluble carbohydrate. Maximum soil moisture deficit (SMD) exceeded 140 mm in all years, with large deficits (> 75 mm) from early June in 1994 and from May in 1995 and 1996. The main effects of drought on partitioning of biomass were for a decrease in the proportion of the crop as lamina in the pre-flowering period, and then earlier retranslocation of stem reserves to grains during the first half of grain filling. Restricted water availability decreased grain yield by 1.83 t/ha in 1994 (P < 0.05), and with more prolonged droughts, by 3.06 t/ha in 1995 (P < 0.001) and by 4.55 t/ha in 1996 (P < 0.001). Averaged over the three years, grain yield responses of the six cultivars differed significantly (P < 0.05). Rialto and Mercia lost only 2.8 t/ha compared with Riband and Haven which lost 3.5 t/ha. Losses for Soissons and Maris Huntsman were intermediate. In the two years with prolonged drought, the biomass depression was on average greater for Haven (6.0 t/ha) than for Maris Huntsman (4.2 t/ha) (P < 0.05). Thus, the grain yield sensitivity of Haven to drought derived, in part, from a sensitivity of biomass growth to drought. Harvest index (HI; ratio of grain to above-ground dry matter at harvest) responses of the six cultivars to irrigation also differed (P < 0.05) and contributed to the yield responses. The smallest decrease in HI of the six cultivars with restricted water availability was shown by Rialto (- 0.033); this partially explained the drought resistance for this cultivar. The largest decrease was for Maris Huntsman (-0.072). The cultivars differed in flowering dates by up to 9 days but these were poorly correlated with grain yield responses to irrigation. Stem soluble carbohydrate at flowering varied amongst cultivars from 220 to 300 g/m(2) in the unirrigated crop; greater accumulation appeared to be associated with better maintenance of HI under drought. It is concluded that high stem-soluble carbohydrate reserves could be used to improve drought resistance in the UK's temperate climate, but that early flowering seems less likely to be useful.