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Background and aims The escalating issue of soil saline-alkalization poses a growing global challenge. Leymus chinensis is a perennial grass species commonly used in the establishment and renewal of artificial grasslands that is relatively tolerant of saline, alkaline, and drought conditions. Nonetheless, reduced seed setting rates limit its propagation, especially on alkali-degraded grassland. Inter-annual variations have an important effect on seed yield and germination under abiotic stress, and we therefore examined the effect of planting year on seed yield components of L. chinensis . Methods We grew transplanted L. chinensis seedlings in pots for two (Y 2 ), three (Y 3 ), or four (Y 4 ) years and collected spikes for measurement of seed yield components, including spike length, seed setting rate, grain number per spike, and thousand seed weight. We then collected seeds produced by plants from different planting years and subjected them to alkaline stress (25 mM Na 2 CO 3 ) for measurement of germination percentage and seedling growth. Results The seed setting rate of L. chinensis decreased with an increasing number of years in pot cultivation, but seed weight increased. Y 2 plants had a higher seed setting rate and more grains per spike, whereas Y 4 plants had a higher thousand seed weight. The effects of alkaline stress (25 mM Na 2 CO 3 ) on seed germination were less pronounced for the heavier seeds produced by Y 4 plants. Na 2 CO 3 caused a 9.2% reduction in shoot length for seedlings derived from Y 4 seeds but a 22.3% increase in shoot length for seedlings derived from Y 3 seeds. Conclusions Our findings demonstrate significant differences in seed yield components among three planting years of L. chinensis under pot cultivation in a finite space. Inter-annual variation in seed set may provide advantages to plants. Increased alkalinity tolerance of seed germination was observed for seeds produced in successive planting years.

Oilseed rape is one of the most important dicotyledonous field crops in the world, where it plays a key role in productive cereal crop rotations. However, its production requires high nitrogen fertilization and its nitrogen footprint exceeds that of most other globally important crops. Hence, increased nitrogen use efficiency (NUE) in this crop is of high priority for sustainable agriculture. We report a comprehensive study of macrophysiological characteristics associated with breeding progress, conducted under contrasting nitrogen fertilization levels in a large panel of elite oilseed rape varieties representing breeding progress over the past 20 years. The results indicate that increased plant biomass at flowering, along with increases in primary yield components, have increased NUE in modern varieties. Nitrogen uptake efficiency has improved through breeding, particularly at high nitrogen. Despite low heritability, the number of seeds per silique is associated positively with increased yield in modern varieties. Seed weight remains unaffected by breeding progress; however, recent selection for high seed oil content and for high seed yields appears to have promoted a negative correlation (r= –0.39 at high and r= –0.49 at low nitrogen) between seed weight and seed oil concentration. Overall, our results reveal valuable breeding targets to improve NUE in oilseed rape.

Floral deception is widespread in orchids, with more than one‐third of the species being pollinated this way. The evolutionary success of deceptive orchids is puzzling, as species employing this strategy are thought to have low reproductive success (less flowers yielding fruits) because of low pollination rates. However, direct measurements of total seed production in orchids – which is a better measure of reproductive success – are scarce due to the extremely small size of their seeds. Here, we quantified seed numbers in 1015 fruits belonging to 48 orchid species from the Pannonian ecoregion (central Europe) and obtained fruit set and thousand‐seed weight data for these species from the literature. We used phylogenetic comparative methods to test the hypothesis that deceptive species should compensate for their lower fruit set by having either more flowers, larger seeds or more seeds in a fruit. Similarly to previous studies, we found that deceptive orchids have substantially lower fruits‐set than nectar‐rewarding ones. Also, we found that deceptive species have more seeds in a fruit but not more flowers or larger seeds compared to nectar‐rewarding ones. Based on our results, deceptive species compensate for their lower fruit set by having higher seed numbers per fruit. As a consequence, their seed numbers per shoot do not differ from that of nectar‐rewarding ones. Together with other benefits of deceptive pollination (e.g. lower energy expenditure due to the lack of nectar production and higher genetic variability due to decreased probability of geitonogamous pollination), our results can explain why deceptive strategies are so widespread in the orchid family. Synthesis. Our results indicate that deceptive orchids can compensate for their lower fruit set by having more (but not larger) seeds in a fruit than rewarding species. These findings highlight possible ways in which plants can increase their reproductive success in face of pollinator limitation. We emphasize that fruit set in itself is an inappropriate measure of the reproductive success of orchids – the total number of seeds per shoot is a much better approximation.

Thousand seed weight (TSW) is an important trait in oilseed rape. Seed shape and seed size, which directly affect seed weight, can be characterized by seed length, seed width, length–width ratio, seed cross-section area, seed circumference, seed diameter and seed roundness. In the present study, a high-density SNP map containing 2812 bins (involving 11,458 SNPs) was used for the QTL analysis of the eight traits. As a result, 177 identified QTLs were detected in five environments, 25 for TSW and 152 for seven seed-shape traits. These QTLs were integrated into 149 consensus QTLs by a meta-analysis, including one (TSW, length–width ratio, seed length and seed width), two (seed circumference and seed diameter) and three (seed roundness) QTLs accounted for more than 10.0% of the phenotypic variation (PV). The further integration of these consensus QTLs resulted in 63 unique QTLs, of which 34 controlled at least two different traits. Notably, the unique QTL uqC2-1 affected all eight traits and explained 6.60–7.57% of the PV. Furthermore, 19 pairs of epistatic loci were detected and explained 2.39–19.17% of the PV. These results provide useful information to increase the understanding of the genetic basis of TSW and seed-shape traits.

Although the level of seed desiccation sensitivity (LSDS) may have an impact on plant species conservation, information is available for <10% of tropical angiosperms. A study was conducted to assess the LSDS of 28 tropical montane species in Sri Lanka. Seeds were extracted from freshly collected fruits. Initial weight was recorded, and thousand seed weight (TSW) was calculated. Seed moisture content (MC) was determined. LSDS was determined using seed desiccation experiments and predicted using the TSW–MC criterion. Seed storage behaviour was predicted using LSDS and storage data and using a model based on phylogenetic affiliation. The relationship between LSDS and seed dormancy, life form and forest strata was evaluated. Fresh seeds of only 12 species germinated to >80%. Although seeds of the other species had >80% viability, only 0–70% germinated due to dormancy. Seeds of five species had MC <15%, indicating desiccation tolerance (DT). Seeds of 12 species lost viability after desiccation, indicating desiccation sensitivity (DS). Seeds of Ardisia missionis, Psychotria gartneri and Psychotria nigra remained viable after desiccation, showing DT. Seeds of 17 species were DS and those of 11 species DT. The TSW of four species was >500 g. Thus, seeds of other species were predicted to be DT by the TSW–MC criterion. A relationship was identified between LSDS and the forest strata of the species. More canopy species produced DS than DT seeds. Since seeds of most of the studied species were DS, these species may be threatened due to prolonged droughts predicted for the region due to climate change.

The hundred-seed weight (HSW) is an important yield component and one of the principal breeding traits in soybean. More than 250 quantitative trait loci (QTL) for soybean HSW have been identified. However, most of them have a large genomic region or are environmentally sensitive, which provide limited information for improving the phenotype in marker-assisted selection (MAS) and identifying the candidate genes. Here, we utilized 281 soybean accessions with 58,112 single nucleotide polymorphisms (SNPs) to dissect the genetic basis of HSW in across years in the northern Shaanxi province of China through one single-locus (SL) and three multi-locus (ML) genome-wide association study (GWAS) models. As a result, one hundred and fifty-four SNPs were detected to be significantly associated with HSW in at least one environment via SL-GWAS model, and 27 of these 154 SNPs were detected in all (three) environments and located within 7 linkage disequilibrium (LD) block regions with the distance of each block ranged from 40 to 610 Kb. A total of 15 quantitative trait nucleotides (QTNs) were identified by three ML-GWAS models. Combined with the results of different GWAS models, the 7 LD block regions associated with HSW detected by SL-GWAS model could be verified directly or indirectly by the results of ML-GWAS models. Eleven candidate genes underlying the stable loci that may regulate seed weight in soybean were predicted. The significantly associated SNPs and the stable loci as well as predicted candidate genes may be of great importance for marker-assisted breeding, polymerization breeding, and gene discovery for HSW in soybean.

The current study was undertaken to identify the sources of tolerance to bruchid in cowpea, by screening a set of germplasm accessions as a source for natural resistance. A total of 103 diverse accessions of cowpea were evaluated for resistance to Callosobruchus maculatus Fab. under no-choice artificial infestation conditions. Significant differences among the cowpea accessions were observed for oviposition, adult emergence, exit holes and per cent seed weight loss (PSWL) caused by the bruchid infestation. The accessions showed variation in physical seed parameters viz., colour, shape, testa texture, length, width and seed hardness. Among the seed biochemical parameters studied, per cent sugar content ranged from 0.322 (IC330950) to 1.493 (IC249137), and per cent phenol content ranged from 0.0326 (EC390261) to 1.081 (EC528423). Correlation studies indicated that PSWL had significant positive correlation ( r = 0.335) with exit holes, oviposition ( r = 0.219), adult emergence ( r = 0.534) and seed roundness ( r = 0.219). Adult emergence had a significant negative correlation with seed hardness ( r = −0.332). Correlation with biochemical parameters indicated that PSWL had a significant positive correlation ( r = 0.231) with sugar content and a significant negative correlation with phenol content ( r = −0.219). None of the accessions were found to be immune to bruchid infestation. However, out of studied accessions, EC528425 and EC528387 were identified as resistant based on PSWL and moderately resistant based on adult emergence. These resistance sources of cowpea germplasm can be used as potential donors for development of bruchid tolerant/resistant cultivars.

In the article, acclimatization of South Korean varieties of soybeans to the soil-climate conditions of the Republic of Uzbekistan and cross-breeding between them has a positive effect. According to our experiments, the combinations F1CH11(-018) x CH30(-969) and F1CH27(-266) x CH30(-969) were observed in F1 hybrids from the main elements of productivity in terms of inheritance of the number of pods per plant. In addition, F1CH11(-018) x CH30(-969) and F1CH27(-266) x CH30(-969) combinations for seed weight per plant showed positive heterosis in all but 3 combinations for lower pod location characters, positive complete and incomplete dominance was observed. Character superiority in the number of seeds per plant in CH30(-969), CH7(-014), CH28(-268) and CH28(-268), F1CH11(-018) x CH30(-969), F1KO20 x CH30 In (-969) combinations, a high index of 1000 seed weight was found in CH7(-014) and K09(339) variety samples. In combinations F1K09(339) x CH30(-969), F1US-25(-622) x CH30(-969), F1CH11(-018) x CH30(-969), F1US-25(-622) x CH30(-969 ), the phenomenon of heterosis was observed in F1CH11(-018) x CH30(-969), F1US-44 (-641) x CH30(-969) and F1KO20 x CH30(-969) combinations. It has been highlighted that the continuation of research on the above-studied variety samples and hybrid combinations will be highly effective in increasing productivity.

To address the problem of low efficiency and automatically sense the phenotypic characteristics of wheat seeds, a wheat seed phenotype detection device was designed to predict thousand seed weight. Five commonly used varieties of wheat seeds were selected for the study, and a wheat seed phenotype detection system was built with a 2 mm sampling hole plate. Grayscale, image segmentation, area filtering and other methods were used to process the image in order to extract and analyse the correlation between thousand seed weight and seven phenotypic characteristics: wheat seed area, perimeter, long axis, short axis, ellipticity, rectangularity, and elongation. The results showed that different varieties of wheat seeds were significantly correlated with different phenotypic characteristics. Among them, the area and short axis for Luomai 26; the area, long axis, short axis, perimeter, and rectangularity for Jinqiang 11; the area and perimeter for Zhoumai 22; the area of Luomai 42; the area, short axis, and perimeter for Bainong 207 were significantly correlated with the thousand seed weight. A multiple linear regression model of thousand seed weight prediction was developed by selecting the significantly correlated phenotypic characteristic. The models showed that the R2 values of the thousand seed weight prediction models for Jinqiang 11 and Bainong 207 were 0.853 and 0.757, respectively; and the R2 values for Luomai 26, Zhoumai 22, and Luomai 42 were less than 0.5. Subsequently, PCA-MLR was used to build a thousand seed weight prediction model, and K-fold cross-validation was used for comparative analysis. Afterwards, three kinds of wheat seeds with 40–50 g thousand seed weight were selected to validate the model. The validation results showed that the more significantly correlated the phenotypic parameters were, the higher the accuracy of the thousand seed weight prediction model. The study provided a set of detection devices and methods for the rapid acquisition of the phenotypic characteristics of wheat seeds and thousand seed weight prediction.

We produced homogeneous lines of 227 pea accessions from the Nordic Genetic Resource Center via single seed descent. The genetic diversity among these, mostly Scandinavian accessions, was investigated using three microsatellite markers, A9, AC58 and AA5. The microsatellites were highly informative and separated 153 of 194 accessions on a Neighbor Joining topology. The high polymorphism information content (PIC) values between 0.87 and 0.91 indicated that the gene bank material contains a large number of pea accessions with different breeding histories. The peas were grown in the field for two years and seed protein content showed variation between 9.3% and 34.1% over the years and accessions, respectively. The mean thousand seed weight was 152.05 g. More than 10 accessions had a protein content above 28%, showing that the collection has potential as breeding nursery for high-protein pea cultivars.