CSIRO Food Futures National Research Flagship, GPO Box 93, North Ryde, NSW 1670, Australia.
J Sci Food Agric. 2011 May;91(7):1298-303. doi: 10.1002/jsfa.4316. Epub 2011 Feb 24.
Dietary fibre lowers the risk of coronary heart disease and colorectal cancer. This survey quantifies mixed link β-glucan (MBG) and arabinoxylan (AX) in wheat and investigates relationships between the grain carbohydrates. MBG and AX contents were measured in 500 and 200 wheat accessions respectively, including diploid, tetraploid and hexaploid genotypes comprising primitive, synthetic and elite lines.
Overall, MBG contents ranged between 1.8 and 18.0 g kg(-1) grain dry weight. In wheat-barley addition lines and triticale hexaploids the levels were 9.0-11.3 and 3.5-9.6 g kg(-1) respectively. The amounts in synthetic wheats were nearer their tetraploid parents than their diploid parents. AX and total non-starch polysaccharide (NSP) contents ranged from 23.7 to 107.5 g kg(-1) and from 31.7 to 136.7 g kg(-1) respectively. Linear regressions showed that the relationships of starch and grain weight with NSP glucose were stronger than those with AX.
The results indicated insufficient genetic diversity in the germplasm surveyed to initiate a breeding programme to increase the amount of MBG in wheat grain to 20 g kg(-1) , a level considered high enough to confer a 10-15% reduction in blood cholesterol.
膳食纤维可降低冠心病和结直肠癌的风险。本研究调查了小麦中混合连接β-葡聚糖（MBG）和阿拉伯木聚糖（AX）的含量，并研究了谷物碳水化合物之间的关系。分别对 500 份和 200 份小麦种质资源进行了 MBG 和 AX 含量的测定，包括二倍体、四倍体和六倍体基因型，包括原始、合成和优良系。
总体而言，MBG 含量范围为 1.8-18.0 g kg(-1) 谷物干重。在小麦-大麦添加系和黑麦六倍体中，含量分别为 9.0-11.3 和 3.5-9.6 g kg(-1)。合成小麦中的含量更接近其四倍体亲本，而不是二倍体亲本。AX 和总非淀粉多糖（NSP）含量分别为 23.7-107.5 g kg(-1) 和 31.7-136.7 g kg(-1)。线性回归表明，淀粉和谷物重量与 NSP 葡萄糖的关系强于与 AX 的关系。
结果表明，所调查的种质资源中遗传多样性不足，无法启动一个旨在提高小麦籽粒中 MBG 含量至 20 g kg(-1) 的育种计划，这一水平被认为足以使血液胆固醇降低 10-15%。
