The ability of wheat cultivars to withstand drought in UK conditions: resource capture
The ability of wheat cultivars to withstand drought in UK conditions: resource capture
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DOI：
10.1017/s0021859601001149
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发表时间：
2001-08-01
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
在英国诺丁汉郡的ADAS Gleadthorpe，于1993/94、1994/95、1995/96年3个干旱季节在壤质中砂上进行试验，研究了6个小麦品种的绿色面积、辐射截留、水分吸收和地上部干物质生长对灌溉的响应。选择引进日期不同的品种（Haven 1987、Maris Huntsman 1969、Mercia 1983、Rialto 1991、Riband 1985和苏瓦松1989）进行开花时间和最大绿色面积的对比。所有年份的最大土壤水分亏缺（SMD）均超过140 mm，从1994年6月初开始出现较大亏缺（> 75 mm），并在1995年和1996年出现更长时间的较大亏缺。有限的水分可用性首先影响冠层扩展，即SMD为74 mm（50%有效水容量; AW），冠层衰老为95 mm（64%AW）。由于长期干旱，1995年和1996年收获时生物量的下降幅度（424-562克/平方米）大于1994年（222克/平方米）。与1995年和1996年这两个最干旱的年份相比，Haven的生物量下降幅度（599 g/m2）大于Maris Huntsman（420 g/m2）（P < 0.05）。Maris Huntsman更好的抗旱性似乎是通过其更高的水分利用效率（WUE）产生的; 6.2 cf. 5.5-5.7 g/m2/mm. Haven对干旱的敏感性可能是由于限制了水分的吸收，降低了辐射利用效率（芸香），加速了衰老.不同的品种在开花长达9天，但开花日期相关性较差，生物量对灌溉的反应。早开花，然而，与有利的分配季节性用水相对于灌浆期。不同品种的最大绿色面积指数（GAI）在4.4 ~ 5.3之间变化（P < 0.01），但消光系数（K）的变化抵消了GAI的差异，因此不同品种的辐射截获量变化不大。因此，绿色面积指数最大值与生长模式或用水模式无关，它们与生物量响应的相关性很差。品种没有不同的最大深度的水提取，他们都提取水到1.65米的深度，每年。它的结论是，早开花和高WUE可能提供的范围，提高抗旱性在英国的温带气候，但小的最大GAI似乎不太有用。
Experiments in three dry seasons (1993/94, 1994/95, 1995/96) on a loamy medium sand at ADAS Gleadthorpe, Nottinghamshire, England tested responses of green area, radiation interception, water uptake and above-ground dry matter growth of six wheat cultivars to irrigation. Cultivars differing in date of introduction (Haven 1987, Maris Huntsman 1969, Mercia 1983, Rialto 1991, Riband 1985 and Soissons 1989) were chosen for contrast in flowering time and maximum green area. Maximum soil moisture deficit (SMD) exceeded 140 mm in all years, with large deficits (> 75 mm) from early June in 1994 and more prolonged large deficits in 1995 and 1996, Restricted water availability first affected canopy expansion at a SMD of 74 mm (50 % available water capacity; AW), and canopy senescence at 95 mm (64% AW). Decreases in biomass at harvest were larger with prolonged droughts in 1995 and 1996 (424-562 g/m(2)) than in 1994 (222 g/m(2)). Compared in the two driest years, 1995 and 1996, the decrease in biomass was greater in Haven (599 g/m(2)) than in Maris Huntsman (420 g/m(2)) (P < 0.05). The better drought resistance of Maris Huntsman appeared to arise through its greater water use efficiency (WUE); 6.2 cf. 5.5-5.7 g/m(2)/mm. The susceptibility of Haven to drought was possibly due to restricted water uptake, depression of radiation use efficiency (RUE) and accelerated senescence. The cultivars differed in flowering by up to 9 days but date of flowering correlated poorly with biomass response to irrigation. Early flowering was, however, correlated with favourable distribution of seasonal water use with respect to the grain filling period. The maximum green area index (GAI) of cultivars varied from 4.4 to 5.3 (P < 0.01), but differences were countered by shifts in the extinction coefficient (K), such that season-long radiation interception varied little. Green area index maxima did not therefore relate to the pattern of growth or water use, and they were correlated poorly with the biomass responses. Cultivars did not differ in their maximum depth of water extraction; they all extracted water to 1.65 m depth in each year. It is concluded that early flowering and high WUE might offer scope for improving drought resistance in the UK's temperate climate, but that small maximum GAI seems less useful.