While the yield potential of rice has increased but little is known about the impact of breeding on grain quality, especially under different levels of N availability. In order to investigate the integrated effects of breeding and N levels on rice quality 12 japonica rice cultivars bred in the past 60 years in the Yangtze River Basin were used with three levels of N: 0 kg N ha− 1, 240 kg N ha− 1, and 360 kg N ha− 1. During the period, milling quality (brown rice percentage, milled rice percentage, and head rice percentage), appearance quality (chalky kernels percentage, chalky size, and chalkiness), and eating and cooking quality (amylose content, gel consistency, peak viscosity, breakdown, and setback) were significantly improved, but the nutritive value of the grain has declined due to a reduction in protein content. Micronutrients, such as Cu, Mg, and S contents, were decreased, and Fe, Mn, Zn, Na, Ca, K, P, B contents were increased. These changes in grain quality imply that simultaneous improvements in grain yield and grain quality are possible through selection. Overall, application of N fertilizer decreased grain quality, especially in terms of eating and cooking quality. Under higher N levels, higher protein content was the main reason for deterioration of grain quality, although lower amylose content might contribute to improving starch pasting properties. These results suggest that further improvement in grain quality will depend on both breeding and cultivation practices, especially in regard to nitrogen and water management.
The rich genetic variation preserved in collections of Aegilops tauschii can be readily exploited to improve common wheat using synthetic hexaploid wheat lines. However, hybrid necrosis, which is characterized by progressive death of leaves or plants, has been observed in certain interspecific crosses between tetraploid wheat and Ae. tauschii. The aim of this study was to construct a fine genetic map of a gene (temporarily named NetJingY176) conferring hybrid necrosis in Ae. tauschii accession Jing Y176. A triploid F1 population derived from distant hybridization between Ae. tauschii and tetraploid wheat was used to map the gene with microsatellite markers. The newly developed markers XsdauK539 and XsdauK561 co-segregated with NetJingY176 on chromosome arm 2DS. The tightly linked markers developed in this study were used to genotype 91 Ae. tauschii accessions. The marker genotype analysis suggested that 49.45% of the Ae. tauschii accessions carry NetJingY176. Interestingly, hybrid necrosis genotypes tended to appear more commonly in Ae. tauschii ssp. tauschii than in Ae. tauschii ssp. strangulata.
Understanding functional relations among plant traits and their modulation by growing conditions is imperative in designing selection strategies for breeding programs. This study assessed trait relationships among 196 common bean genotypes exposed to stresses for drought and field infestation of bean fly or bean stem maggot (BSM). The study was carried out at two locations and data was analyzed with linear correlation, path coefficient and genotype × trait biplot analyses. Multiple trait data related to mechanisms of drought and bean fly tolerance were collected on 196 genotypes grown under i) water deficit at mid-pod fill, or ii) unprotected against bean fly; iii) irrigated, well watered conditions, or iv) bean fly protection with chemicals. Seed yield exhibited positive and significant correlations with leaf chlorophyll content, vertical root pulling resistance, pod harvest index, pods per plant and seeds per pod at both phenotypic and genotypic levels under stress and non-stress conditions. Genotypic correlations of traits with seed yield were greater than their respective phenotypic correlations across environments indicating the greater contribution of genotypic factors to the trait correlation. Pods per plant and seeds per pod had high positive direct effects on seed yield both under stress and non-stress whereas pods per plant had the highest indirect effect on seed yield through pod harvest index under stress. In general, our results suggest that vertical root pulling resistance and pod harvest index are important selection objectives for improving seed yield in common beans under non-stress and stress conditions, and particularly useful for drought and BSM tolerance evaluation.
Rice (Oryza sativa L.) is one of the most important staple crops in China. Increasing atmospheric greenhouse gas concentrations and associated climate change may greatly affect rice production. We assessed the potential impacts of climate change on cold rice production in the Heilongjiang province, one of China's most important rice production regions. Data for a baseline period (1961-1990) and the period 2010-2050 in A2 and B2 scenarios were used as input to drive the rice model ORYZA2000 with and without accounting for the effects of increasing atmospheric CO2 concentration. The results indicate that mean, maximum, and minimum temperature during the rice growing season, in the future period considered, would increase by 1.8 °C under the A2 scenario and by 2.2 °C under the B2 scenario compared with those in the baseline. The rate of change in average maximum and minimum temperatures would increase by 0.6 °C per 10-year period under the A2 scenario and by 0.4 °C per 10-year period under the B2 scenario. Precipitation would increase slightly in the rice growing season over the next 40 years. The rice growing season would be shortened and the yield would increase in most areas in the Heilongjiang province. Without accounting for CO2 effect, the rice growing season in the period 2010-2050 would be shortened by 4.7 and 5.8 days, and rice yields would increase by 11.9% and 7.9%, under the A2 and B2 scenarios, respectively. Areas with simulated rice yield increases greater than 30.0% were in the Xiaoxing'an Mountain region. The simulation indicated a decrease in yield of less than 15% in the southwestern Songnen Plain. The rate of change in simulated rice yield was 5.0% and 2.5% per 10 years under the A2 and B2 scenarios, respectively. When CO2 effect was accounted for, rice yield increased by 44.5% and 31.3% under the A2 and B2 scenarios, respectively. The areas of increasing yield were sharply expanded. The area of decreasing yield in the western region of Songnen Plains disappeared when increasing CO2 concentration was considered. The stability of rice yield would increase from 2010 to 2050. Overall, the simulation indicates that rice production will be affected positively by climate change in the next 40 years in the Heilongjiang province, China.
The objective of this study was to evaluate the effects of wheat variety, food processing, and milling method on antioxidant properties. Black wheat variety Heibaoshi 1 had the highest total phenolic content (659.8 μg gallic acid equivalents g− 1), total flavonoid content (319.3 μg rutin equivalents g− 1), and antioxidant activity, whereas light purple wheat variety Shandongzimai 1 had the lowest total flavonoid content (236.2 μg rutin equivalents g− 1) and antioxidant activity. Whole wheat flour and partially debranned grain flour had significantly higher total phenolic contents, total flavonoid contents, and antioxidant activity than refined flour (P < 0.05). Compared with flour, total phenolic contents, total flavonoid contents and antioxidant activity decreased in noodles and steamed bread, whereas noodles had slightly higher total phenolic and flavonoid content than steamed bread. Antioxidant activities (by ferric reducing ability of plasma assay) of steamed bread made from whole wheat flour, partially debranned grain flour, and refined flour were 23.5%, 21.1%, and 31.6% lower, respectively, than the corresponding values of flour. These results suggested that black whole wheat flour and partially debranned grain flour are beneficial to human health.
EST sequences of Mentha piperita available in the public domain (NCBI) were exploited to develop SSR markers. A total of 1316 ESTs were assembled into 155 contigs and 653 singletons and of these, 110 sequences were found to contain 130 SSRs, with a frequency of 1 SSR/3.4 kb. Dinucleotide repeat SSRs were most frequent (72.3%) with the AG/CT (43.8%) repeat motif followed by AT/AT (16.2%). Primers were successfully designed for 68 SSR-containing sequences (62.0%). The 68 primers amplified 13 accessions of M. piperita and 54 produced clear amplicons of the expected size. Of these 54, 33 (61%) were found to be polymorphic among M. piperita accessions, showing from 2 to 4 alleles with an average of 2.33 alleles/SSR, and the polymorphic information content (PIC) value varied between 0.13 and 0.51 (average 0.25). All the amplified SSRs showed transferability among four different species of Mentha, with a highest in Mentha arvensis (87.0%) and minimum in Mentha citrata (37.0%). The newly developed SSRs markers were found to be useful for diversity analysis, as they successfully differentiated among species and accessions of Mentha.
Allene oxide cyclase (AOC, E 5.3.99.6) is an essential enzyme in the jasmonic acid (JA) biosynthetic pathway and mediates a wide range of adaptive responses. In this report, five AOC genes (GhAOC1-GhAOC5) were cloned from upland cotton (Gossypium hirsutum L.), sequenced, and characterized. Real-time PCR analysis indicated that the transcripts of GhAOCs were abundantly expressed in roots and less in fibers, and regulated in cotton plants under methyl jasmonate (MeJA) and CuCl2 stresses. To investigate the role of GhAOC under copper stress, transgenic Arabidopsis plants overexpressing cotton GhAOC1 under control of the Cauliflower mosaic virus 35S (CaMV 35S) promoter were generated. Compared to untransformed plants, GhAOC1-overexpressing Arabidopsis thaliana plants exhibited markedly higher survival rate, shoot fresh weight, shoot dry weight, and photosynthetic efficiency, and reduced cell membrane damage and lipid peroxidation under copper stress. This study provides the first evidence that GhAOC1 plays an important role in copper stress tolerance.
Naked oat is a unique health food crop in China. Using 202 F2 individuals derived from a hybrid between the variety 578 and the landrace Sanfensan, we constructed a genetic linkage map consisting of 22 linkage groups covering 2070.50 cM and including 208 simple sequence repeat (SSR) markers. The minimum distance between adjacent markers was 0.01 cM and the average was 9.95 cM. Each linkage group contained 2-22 markers. The largest linkage group covered 174.40 cM and the shortest one covered 36.80 cM, with an average of 94.11 cM. Thirty-six markers (17.3%) showing distorted segregation were distributed across linkage groups LG5 to LG22. This map complements published oat genetic maps and is applicable for quantitative trait locus analysis, gene cloning and molecular marker-assisted selection.
Phytic acid is the major storage form of phosphorus in cereals. It binds with nutritionally important metals and affects mineral bioavailability. The present study analyzed phytic acid, inorganic phosphorus (IP) content, seed weight, and grain yield in 98 sorghum landraces and varieties grown in two environments to evaluate genotypic and environmental effects and to determine trait stability. Genotypic effects and genotype × interaction were significant for phytic acid concentration and yield components. A promising landrace, Malkhed-1, had the lowest phytic acid (0.015 mg g− 1) concentration, with a higher yield (70.02 g plant− 1), than the check variety M-35-1 in both environments. Similarly, among the varieties, Phule Maulee showed the lowest phytic acid (0.07 mg g− 1) and a higher grain yield of 53.15 g plant− 1 in both environments. Phytic acid and IP were negatively correlated (r = − 0.34), whereas grain yield and seed weight were positively correlated (r = 0.20). Cluster analysis based on seed phosphorus traits and yield components identified five and six clusters, respectively. Genotypes containing low phytic acid with high yield identified in this study would be helpful for increasing the bioavailability of mineral nutrients.
To evaluate the accumulation of oil and fatty acids in coriander during fruit ripening, a field experiment was conducted under organic cultivation conditions in Auch (near Toulouse, southwestern France) during the 2009 cropping season. The percentage and composition of the fatty acids of coriander were determined by gas chromatography. Our results showed that rapid oil accumulation started in early stages (two days after flowering, DAF). Twelve fatty acids were identified. Saturated and polyunsaturated acids were the dominant fatty acids at earlier stages (2-12 DAF), but decreased after this date. After this stage, petroselinic acid increased to its highest amount at 18 DAF. In contrast, palmitic acid followed the opposite trend. Saturated and polyunsaturated fatty acids decreased markedly and monounsaturated fatty acids increased during fruit maturation. It appears that the fruit of coriander may be harvested before full maturity.
