Shoot growth, root growth and grain yield of bread and durum wheat in South Australia
Shoot growth, root growth and grain yield of bread and durum wheat in South Australia
复制标题
南澳大利亚面包和硬粒小麦的芽生长、根生长和籽粒产量
DOI：
10.1071/ea98184
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发表时间：
1999
影响因子：
--
通讯作者：
G. Hollamby
中科院分区：
文献类型：
--
作者：
A. Zubaidi;G. McDonald;G. Hollamby
摘要在南澳，在水分充足和肥沃的条件下，硬粒小麦的产量高于面包小麦，但在该州的谷物带的大部分地区，硬粒小麦的产量相对于面包小麦来说是低的。在2个地点进行了3年多的3个试验，以比较面包小麦和硬粒小麦的生长和产量，并调查2种谷物相对产量差异的一些原因。硬粒小麦产量低于面包小麦时，年降雨量小于约450毫米，或当该网站的面包小麦的平均产量小于250克/平方米。与面包小麦相比，硬粒小麦具有较差的早期活力，这与较少的分蘖/m2，并产生较少的粒/m2。在有利的籽粒灌浆条件下，硬粒小麦比面包小麦产生更大的籽粒，但其粒重在不同地点和季节之间变化更大，因此，2种谷物的相对产量在很大程度上取决于粒重。例如，在多雨的年份，硬粒小麦的产量比面包小麦高20%，尽管每平方米的籽粒产量少16%，因为它的籽粒较大（52比36毫克）。在2个干旱年份，硬粒小麦和面包小麦的粒重相似（硬粒小麦和面包小麦的平均粒重：40对37毫克; 30对33毫克），因此硬粒小麦无法克服每平方米粒数较少的限制，其产量与面包小麦相似或更低。硬粒小麦和面包小麦30 cm以下的根长密度较低。硬粒小麦的根长密度与面包小麦相当或更低，每克根干物质的长度更低，表明根的细分程度更低。这表明，硬粒小麦有时可能比面包小麦更不能利用底土中的水分和养分储备，因为根系较小。这对于似乎比面包小麦更依赖于产生大籽粒以获得高产的作物来说是不期望的特性。通过遗传改良或农艺手段提高硬粒小麦产量的努力，应侧重于降低开花后时期的胁迫水平，以尽量减少对籽粒生长的限制。提高作物的早期活力，培育成熟度适当、对根病具有足够抗性的品种，以及改善根在底土中的生长和功能，可能是理想的特性。
Summary. In South Australia, durum wheat yields more than bread wheat under well-watered and fertile conditions, but over much of the state’s cereal belt the yields of durum wheat, relative to bread wheat, are low. Three experiments were conducted over 3 years at 2 sites to compare the growth and yield of bread and durum wheat and to investigate some of the reasons for the differences in the relative yields of the 2 cereals. Durum wheat yielded less than bread wheat when annual rainfall was less than about 450 mm or when the site mean yield for bread wheat was less than 250 g/m2. Compared with bread wheat, durum wheat had poorer early vigour, which was associated with fewer tillers/m2, and produced fewer kernels/m2. Under favourable grain filling conditions, durum wheat produced larger kernels than bread wheat but its kernel weight was more variable across sites and seasons and consequently, the relative yields of the 2 cereals depended largely on kernel weight. For example, in a wet year, durum wheat yielded 20% more than bread wheat, despite producing 16% fewer kernels/m2, because of its larger kernels (52 v. 36 mg). In 2 drier years, kernel weights of durum and bread wheat were similar (durum and bread wheat mean kernel weights: 40 v. 37 mg; 30 v. 33 mg) and so durum was unable to overcome the limitation of fewer kernels/m2 and its yields were similar to or less than bread wheat. Root length densities of durum and bread wheat below 30 cm were low. Durum wheat had an equivalent or lower root length density than bread wheat and lower length per gram of root dry matter, indicating less finely divided roots. This suggests that durum wheat may sometimes be less able than bread wheat to utilise moisture and nutrient reserves in the subsoil because of a smaller root system. This is an undesirable characteristic for a crop that appears to be more reliant than bread wheat on producing large kernels for high yields. Efforts to improve the yield of durum wheat, either through genetic improvement or by agronomic means, should focus on reducing the levels of stress during the post anthesis period so that limitations to kernel growth are minimised. Improving the early vigour of the crop, having cultivars of the appropriate maturity and with adequate levels of resistance to root disease, and improving root growth and function in the subsoil are likely to be desirable characteristics.