Search

Alternative physiological strategies can increase protein concentration in soybean: (i) more‐than‐proportional increases in seed protein content (mg seed−1) relative to increases in carbohydrate and oil content in large‐seeded genotypes or (ii) more‐than‐proportional reductions in carbohydrate and/or oil content relative to protein content reductions in small‐seeded genotypes. Because these strategies differentially affect crop growth and development, we hypothesized that populations developed from high‐protein (HP) parents with contrasting seed sizes will present differences in how seed yield and protein concentration correlate. To test this, three breeding strategies were developed by mating high‐yielding cultivars and HP ones that differ in seed sizes, reflecting the alternative strategies mentioned above. Neither tested crossing strategies showed differences in their correlation values between seed yield and protein concentration, as initially expected. Nevertheless, populations developed from crossing a HP‐small‐seeded parent to a HP‐large‐seeded one showed the highest number of transgressive segregants for protein yield. Our results showed that parent selection based on seed size has no beneficial effects on the development of high‐yielding, HP soybean populations, but it might affect the number of transgressive segregants for protein yield. [ABSTRACT FROM AUTHOR]

Increasing soybean yield plays a key role in meeting the high demand for protein in Europe and other countries. The aim of this study was to dissect the genetic architecture underlying seed yield, plant height, protein yield and thousand‐seed weight in early‐maturing soybean. To this end, we performed QTL mapping based on 944 RILs derived from a half‐diallel crossing design of five parents. We identified five to eight QTL for each of the four agronomic traits and some explained a considerable proportion of the genotypic variance. The three major QTL showed pleiotropic effects on two or more traits. Fine characterization revealed the maturity genes E1 and E3, and the stem growth habit gene Dt2 as likely candidates underlying these QTL. In general, the allele increasing seed yield also resulted in taller plants, which needs to be considered during selection due to an increased risk of lodging. Collectively, our results underline the strong effect of some loci like the E1 gene on a range of traits including seed yield, making them attractive targets for a marker‐assisted selection. [ABSTRACT FROM AUTHOR]

Wheat grain protein content ( GPC) is important for human nutrition and has a strong influence on the quality of pasta and bread. The objective of this study was to analyse the introduction of the Gpc- B1 allele into two Argentinean bread wheat cultivars. Near-isogenic lines were developed in ' Pro INTA Oasis' and ' Pro INTA Granar' using marker-assisted selection. Gpc- B1 lines showed a significant (P = 0.01) increase in GPC and a significant (P = 0.001) decrease in grain weight in comparison with control lines without Gpc- B1. Differences in yield were not significant (P = 0.49) between lines. Gpc- B1 lines significantly reduced (P = 0.02) straw nitrogen concentration at maturity and significantly increased (P = 0.02) the nitrogen harvest index. When data were analysed by genotype and environment, differences in some analysed parameters were found, indicating that Gpc- B1 expression may be affected by different genetic backgrounds and environmental conditions. These results suggest that the introgression of the Gpc- B1 allele into Argentinean wheat germplasm could be a valuable resource for improving GPC with no detrimental effect on grain yield. [ABSTRACT FROM AUTHOR]