Grassland Science最新文献

Naturally occurring forage species in the high-altitude pasturelands of Western Himalaya are traditionally being utilized for feeding of livestock. However, the nutritional quality evaluation and validation of their potential as feed for livestock needs to be undertaken. Here, we evaluated proximate compositions, minerals and amino acids (AAs) of five high-altitude forage species, namely, Festuca kashmiriana L., Medicago sativa L., Trifolium pratense L., Medicago falcate L. and Melilotus indica L. The results revealed that proximate compositions, mineral and AAs varied significantly among the forage species. The carbohydrate, crude protein, moisture content, crude fat, crude fiber, crude ash, total phenol, oil absorption capacity and water absorption capacity were found in the range of 17.44–37.27 mg/100 mg, 3.34–14.71 mg/100 mg, 88.73%–90.72%, 0.98–2.32 mg/100 mg, 11.16–24.16%, 7.71–34.49%, 292.50–488.12 μg/100 mg, 3.91–4.67 g/g and 2.64–3.41 g/g, respectively. Elemental composition showed that calcium was the predominant element among the minerals (13.91–132.05 mg/kg DM) followed by magnesium (4.60–12.92 mg/kg DM), iron (2.04–76.13 mg/kg DM) and zinc (1.07–2.17 mg/kg DM). Furthermore, we found that these high-altitude forage species are rich in essential AAs like histidine, tryptophan, valine, leucine, phenylalanine and to some extent isoleucine and tyrosine. In addition, these five species showed distinct proteomes but shared a similar functional group. The proteome profiling of these forage species will help to understand the molecular basis of nutritional enrichment and stress tolerance potential against harsh environmental conditions of high altitudes. Overall, we conclude that traditionally used high-altitude forage species are nutritionally rich and can be recommended as part of the daily nutritive feed for livestock animals.

In order to make good use of Pennisetum grasses to relieve the shortage of animal feed, the nutrients, silage fermentation quality, and Cornell Net Carbohydrate and Protein System (CNCPS) protein fractions of Pennisetum spp. were evaluated in this study. Four Pennisetum cultivars of Reyan-4, Mott, Guimu-1, and MT-1 were harvested at the first cut and second cut, and they were wilted and ensiled for the analyses of fermentation quality and protein fractions. The first-cut grasses had higher crude protein (CP), water-soluble carbohydrate (WSC) contents, and lower detergent fiber contents than the second cut ones. Mott had higher CP content. Reyan-4 and MT-1 contained higher WSC contents, and their silages had lower pH and ammonia nitrogen (NH₃-N) content, higher lactic acid content than Mott and Guimu-1 silages. Wilting increased pH and NH₃-N contents and decreased lactic acid contents of both cut silages. The CNCPS analysis showed that fresh MT-1 of either first or second cut had more evenly distributed protein fractions than other three grasses. Wilting and ensiling increased nonprotein nitrogen contents and decreased unavailable protein contents of four grasses. Four cultivars at the first cut contained more CP and less fiber than those at the second cut. Reyan-4 and MT-1 had better fermentation quality of silage than Mott and Guimu-1; the latter might need additives to improve fermentation quality at ensiling.

The genetic diversity of the Vicia (Vicia L.) genus was analyzed using simple sequence repeat (SSR) markers. A total of 201 sampled individuals from 12 Vicia were assayed to study the genetic diversity and polymorphisms using 12 simple sequence repeat markers; 115 alleles were identified. The average observed heterozygosity (Ho) and the average expected heterozygosity (He) were 0.4283 and 0.6941, respectively. The polymorphic information content (PIC) varied from 0.8739 (V81) to 0.9579 (V97), with a mean of 0.9033, indicating that the markers were highly informative. Moreover, cluster and principal coordinate analysis (PCoA) divided the 12 species into three main clusters. Structure analysis and PCoA of Vicia narbonensis and Vicia tibetica agreed well with the cluster analysis results, and analysis of molecular variance (AMOVA) results revealed that 89% genetic variation was observed within the population and 11% was among the population. These results clarify the genetic diversity and population structure of the Vicia, providing useful information for understanding genetic variability and establishing a foundation for future breeding programs and genetic improvement.

We investigated the maize grain yield in response to nitrogen topdressing at different planting densities and planting patterns (twin row, TR; narrow row, NR; and conventional row, CR) over 3 years using early-maturing cultivars. The P8025 grain yield was higher with a nitrogen topdressing of 6 g/m² (N6) than without a nitrogen topdressing (N0) at all planting densities in 2017, 2018, and 2019. The difference between the nitrogen topdressing treatments was largest at a planting density close to 10 plants per square meter, which resulted in the highest grain yield in the N0 plot. The rank order for the grain yields among planting patterns was TR ≥ NR > CR in the three analyzed years. Changes in grain yield associated with planting densities followed significant negative quadratic regression curves for all planting patterns. In both the N0 and N6 plots, the grain yield response to planting density was more stable for TR cultivation than for CR and NR cultivation. The rank order for the nitrogen use efficiency (NUE) among planting patterns was TR ≥ NR ≥ CR. The differences in the NUE among planting patterns were higher at higher planting densities. The high NUE observed for TR and NR cultivation was due to the high topdressed nitrogen absorption rate (Nab) at a planting density less than 8.9 plants per square meter as well as the efficiency of the grain yield increase resulting from absorbed nitrogen (Ngy) at a planting density greater than 10.3 plants per square meter. The higher NUE for TR cultivation than for NR cultivation at 12.1 plants per square meter was because of a difference in Ngy and was unrelated to Nab. These results suggest that the improvement of planting pattern (TR, NR) can enhance the effect of topdressed nitrogen on grain yield in maize due to the increase of Nab or Ngy according to the planting density.

The ZjHSP18.9 gene was isolated from Zoysiagrass by homologous cloning based on publicly available transcriptome database. Sequence alignment analysis revealed that ZjHSP18.9 protein contains a classic Hsp23/ACD domain. Phylogenetic analysis and subcellular localization prediction suggested that ZjHSP18.9 belongs to cytosolic class VI subfamily. The expression profiles of ZjHSP18.9 in leaf and root after abiotic stress or Abscisic Acid (ABA) treatment was investigated using quantitative real-time polymerase chain reaction. The results showed that the expression level of ZjHSP18.9 in leaf was higher than that in root. The expression of ZjHSP18.9 was strongly induced by high temperature in leaf; the ZjHSP18.9 expression level was up-regulated in both leaf and root by the treatment of low temperature, salt and heavy metal, while down-regulated under the treatment of drought and ABA. The gene expression profiles indicated that ZjHSP18.9 may play an important role in Zoysiagrass response to environmental stress including extreme temperature, salinity, water deficiency and heavy metal through ABA dependent and/or independent pathway.

The propagation and seed multiplication of site-adapted and drought-tolerant grass varieties are essential to provide high-quality forage in temperate grasslands. A field experiment was conducted from 2016–2019 on orchardgrass (Dactylis glomerata L.) in the province of Styria, Austria. Treatment effects of sulfur, fungicide application and a plant growth regulator, singly and in combination, on seed yield and its reproduction parameters were tested under two different fertilizer nitrogen management systems (single application [N1] and split application [N2]). In terms of seed yield, a combination of all treatments compared to fertilization-only treatment showed a significant increase of 22% under N2 fertilization. In terms of the thousand seed weight, the fungicide treatments and a combination of all treatments performed significantly better than other treatments within N1 and N2. The use of fungicide and a combination of all treatments also significantly increased the germination capacity in N1. Therefore, a combination of all plant protection treatments is recommended to optimize seed yield, thousand seed weight and germination capacity.

The aim of this study was to explore the response of the stoichiometric and photosynthetic characteristics of a dominant plant species in a typical grassland to changes in precipitation. Rain shelter technology was used to simulate 50%, 100%, and 150% of natural rainfall. The photosynthetic rate (Pn), intercellular CO₂ concentration (Ci), transpiration rate (Tr), stomatal conductance (Gs), and ecological stoichiometry of the rhizosphere soil and Stipa bungeana at different growth stages were measured in May, July), and September, 2019 after 2 years of rainfall control. The results showed that the aboveground carbon (C) content of plants grown under 150% precipitation was significantly higher than that of plants grown under 100% precipitation in September. The aboveground nitrogen (N) content of plants under 50% precipitation was significantly higher than the plants grown under 100% precipitation. Under all different precipitation treatments, the aboveground C:N ratio was the lowest (16.4–19.6) in May. The range of average aboveground C: phosphorous (P) ratio was 373.7–617.8, and the N:P ratio in the descending order was July > May > September. The 50% precipitation treatment promoted the highest accumulation of underground C at all the growth stages. The productivity of the grassland under the 100% and 150% precipitation treatments was limited by the rhizosphere soil N and P. The underground C, P, C:P, and aboveground C:N ratios were sensitive indicators. Aboveground and underground N:P ratio showed the strongest significant correlation (P < 0.001), and the correlation between underground stoichiometry and rhizosphere soil P (P < 0.001) was stronger than that with rhizosphere soil N (P < 0.05). The correlation between Ci and stoichiometry was opposite in direction to the correlation between Pn, Tr, Gs, and stoichiometry. The research results will provide a scientific reference for understanding of the material cycle and judgment of vegetation nutrient limitations in the Loess Plateau.

To reveal the genetic diversity and structure of cultivars and breeding materials of diploid Italian ryegrass (Lolium multiflorum Lam.) in Japan, using genome-wide allele frequency data obtained by genotyping by random amplicon sequencing, direct of pooled DNA, we investigated genetic diversity among and within 89 accessions. We selected 2629 reliable alleles at 456 polymorphic loci to evaluate allele frequency in each accession. Results of hierarchical cluster analysis based on Nei's standard genetic distance and of principal component analysis and nonhierarchical cluster analysis based on the complete set of allele frequencies classified the accessions into a large group including major Japanese cultivars and their ancestral landraces with a wide range of maturity, and a small group with mainly medium maturity, including ‘Gulf’, introduced from overseas. The genetic relationships fully reflected the kinship inferred from the breeding history in Japan. Mean expected heterozygosity (H_E) and number of alleles per locus (A) were evaluated as indices of genetic diversity within each accession. We found a significant negative correlation between the year of application for varietal registration and H_E or A in 14 early-maturing Japanese cultivars. The genetic diversity profile can be used for breeding to maintain or increase the diversity within cultivars or breeding materials.

Root and stalk rot (RSR) of maize (Zea mays L.) plants, caused by soil-borne disease pathogens of the genus Pythium, can get worse in global warming. It has been known that the resistance of F₁ hybrids often disaccords with those of their parental inbreds, which makes it difficult to develop resistant hybrids effectively. Best linear unbiased prediction (BLUP) is a standard mixed model equation, which is fitted for predicting hybrid performance by the parental inbreds of maize. The objective of this study was to evaluate simple parental-progeny-based BLUP in predicting single-cross performance and to determine the importance of general combining ability of the resistance to Pythium RSR. The performance prediction of the parental inbreds from BLUP was consistent with empirical knowledge and was determined mostly useful, despite not using a coefficient of coancestry. Correlation coefficients between breeding values from BLUP and actual field data for hybrids, across different experiments from 2018 to 2019, were relatively high (R = 0.854 and 0.703, respectively). These results indicate the potential of the parental-progeny-based BLUP for maize single-cross performance. This is the first report in predicting the resistance to this disease with BLUP, and the findings can be applied to routine breeding programs as well as to genome-wide molecular polymorphism data to contribute to the future breeding programs.

Insufficient forage supply from natural rangelands during the dry season hampers ruminants' performance in the derived savanna zone of Nigeria. Therefore, to provide alternative feed resources, we evaluated silage potential of Columbus grass (Sorghum almum Parodi) at boot, dough and maturity stages for 4-, 8-, 12- and 16-week ensiling durations, in a 3 × 4 factorial experiment. The dry matter yield (DMY) was determined at each harvest stage, and the forages were subsequently ensiled. The results revealed that the DMY of S. almum at maturity was 8.98% and 18.67% higher than at dough and boot stages, respectively (p < 0.05). The silages were ranked “good silage” based on physical characteristics. Silage pH decreased with advancing ensiling duration from 4 to 16 weeks in boot (5.25–4.63), dough (5.63–4.11) and maturity (5.42–4.91), with a corresponding increase in lactic and volatile fatty acids. Crude protein (CP) was higher in forages ensiled at maturity and increased with ensiling duration after initial decline from 4 to 8 weeks. Neutral detergent fiber (NDF) and hemicellulose increased quadratically from boot to dough and subsequently declined at maturity. Growth stage, ensiling duration and their interactions influenced the macrominerals' content (p < 0.05). Silages' dry matter intake (DMI) declined from boot to dough stage across the ensiling durations, and except for 8 weeks, the DMI increased at maturity by 6.71%, 5.54% and 7.19% in 4, 12 and 16 weeks, respectively. Therefore, owing to the lower NDF and high DMY, CP and DMI of S. almum ensiled at maturity for 16 weeks, it could guarantee a quantitative and qualitative forage supply to maintain optimum animal performance throughout the dry season.