[Effects of water-nitrogen combination on dry matter, nitrogen accumulation and yield of winter wheat]. / æ°´æ°®ç»„åˆå¯¹å†¬å°éº¦å¹²ç‰©è´¨åŠæ°®ç´ ç§¯ç´¯å’Œäº§é‡çš„å½±å“.

In two growing seasons of wheat (2015-2017), we conducted a field trial with Taishan 28 in Tai'an Academy of Agricultural Science Feicheng experimental base, Tai'an City, Shandong Province. There were four irrigation levels of 150 (A1), 300 (A2), 450 (A3), and 600 (A4) m3·hm-2, and four nitrogen application levels of 90 (B1), 135 (B2), 180 (B3), and 225 (B4) kg·hm-2. We examined the effects of the combination effects of irrigation and nitrogen on dry matter accumulation and transport, nitrogen accumulation and transport, water consumption and utilization, photosynthetic characteristics, wheat grain yield and yield components of wheat. The results showed that dry matter accumulation, nitrogen accumulation, vegetative organs production, storage and the transportation volume to grains of the dry matter and nitrogen, and dry matter and nitrogen accumulation of grain in the mature stage of wheat all reached the maximum in A3B3 treatment, which were significantly different from other treatments. Under all the nitrogen treatments, soil water consumption in the 60-200 cm soil layer was A3>A4>A2>A1. Water use efficiency and nitrogen use efficiency in A3B3 treatment were higher than that under A3B4, A4B3 and A4B4. The net photosynthetic rate, stomatal conductance and transpiration rate of flag leaves from 7 to 28 days after flowe-ring were all significantly higher in A3B3 treatment, which was conducive to the photosynthetic synthesis of carbohydrates in wheat. The interaction effect of water and nitrogen addition significantly affected grain yield and yield components. Wheat yield was the highest in A3B3 treatment which reached at 9400 kg·hm-2. In conclusion, the treatment with irrigation of 450 m3·hm-2 and nitrogen of 180 kg·hm-2 could significantly improve dry matter and nitrogen accumulation, and promote transportation volume of the dry matter and nitrogen to grain. Compared with the high water and nitrogen treatment, it could effectively increase water use efficiency and nitrogen use efficiency, enhance photosynthetic capacity of flag leaf, produce more carbohydrate, and increase grain yield.

Molecular genetic analysis of grain protein content and flour whiteness degree using RILs in common wheat.

Grain protein content (GPC) and flour whiteness degree (FWD) are important qualitative traits in common wheat. Quantitative trait locus (QTL) mapping for GPC and FWD was conducted using a set of 131 recombinant-inbred lines derived from the cross 'Chuan 35050 × Shannong 483' in six environmental conditions. A total of 22 putative QTLs (nine GPC and 13 FWD) were identified on 12 chromosomes with individual QTL explaining 4.5-34.0% phenotypic variation. Nine QTLs (40.9%) were detected in two or more environments. The colocated QTLs were on chromosomes 1B and 4B. Among the QTLs identified for GPC, QGpc.sdau-4A from the parent Shannong 483 represented some important favourable QTL alleles. QGpc.sdau-2A.1 and QFwd.sdau-2A.1 had a significant association with both GPC and FWD. The markers detected on top of QTL regions could be potential targets for marker-assisted selection.

Enrichment of a common wheat genetic map and QTL mapping for fatty acid content in grain.

DArT and SSR markers were used to saturate and improve a previous genetic map of RILs derived from the cross Chuan35050 × Shannong483. The new map comprised 719 loci, 561 of which were located on specific chromosomes, giving a total map length of 4008.4 cM; the rest 158 loci were mapped to the most likely intervals. The average chromosome length was 190.9 cM and the marker density was 7.15 cM per marker interval. Among the 719 loci, the majority of marker loci were DArTs (361); the rest included 170 SSRs, 100 EST-SSRs, and 88 other molecular and biochemical loci. QTL mapping for fatty acid content in wheat grain was conducted in this study. Forty QTLs were detected in different environments, with single QTL explaining 3.6-58.1% of the phenotypic variations. These QTLs were distributed on 16 chromosomes. Twenty-two QTLs showed positive additive effects, with Chuan35050 increasing the QTL effects, whereas 18 QTLs were negative with increasing effects from Shannong483. Six sets of co-located QTLs for different traits occurred on chromosomes 1B, 1D, 2D, 5D, and 6B.