The high labor demand during rice seedling cultivation and transplantation poses a significant challenge in advancing machine-transplanted rice cultivation. This problem may be solved by increasing the seeding rate during seedling production while reducing the number of seedling trays. This study conducted field experiments from 2021 to 2022, using transplanting seedling ages of 10 and 15 days to explore the effects of 250, 300, and 350 g/tray on the seedling quality, mechanical transplantation quality, yields, and economic benefits of rice. The commonly used combination of 150 g/tray with a 20-day seedling age in rice production was used as CK. The cultivation of seedlings under a high seeding rate and short seedling age significantly affected seedling characteristics, but there was no significant difference in seedling vitality compared to CK. The minimum number of rice trays used in the experiment was observed in the treatment of 350–10 (300 g/tray and 10-day seedling age), only 152–155 trays ha–1, resulting in a 62% reduction in the number of trays needed. By increasing the seeding rate of rice, missed holes during mechanical transplantation decreased by 2.8 to 4%. The treatment of 300–15 (300 g/tray and 15-day seedling age) achieved the highest yields and economic gains. These results indicated that using crop straw boards can reduce the application of seedling trays. On that basis, rice yields can be increased by raising the seeding rate and shortening the seedling age of rice without compromising seedling quality.
Genotype imputation is essential for increasing marker density and maximizing the utility of existing SNP array data in animal breeding. Although a wide range of software is available for genotype imputation, a comprehensive benchmark in pigs is still lacking. In this study, we benchmarked 24 combinations of genotype imputation software for SNP arrays in pigs, comprising six independent pre-phasing software (fastPHASE, MaCH, BIMBAM, Eagle, SHAPEIT, Beagle) and four distinct imputation software (pbwt, Minimac, IMPUTE, Beagle), using 1,602 whole-genome sequencing (WGS) pigs from a multibreed pig genomics reference panel (PGRP) in PigGTEx. Our results indicated that the combination of Beagle for pre-phasing and Minimac for imputation achieves the highest imputation accuracy with a concordance of 0.983, especially for low-frequency SNPs (MAF<0.05). Finally, we proposed three recommended strategies: i) the combination of Beagle and Minimac is optimal for achieving the highest accuracy; ii) the combination of Beagle and Beagle is recognized for its convenience and relatively high accuracy despite it being memory-intensive; iii) the combination of Eagle and pbwt is feasible for its minimal computational cost with relatively high accuracy. This study provides valuable insights for implementing genotype imputation for pig SNP arrays toward sequence data and offers a basis for applications in livestock and poultry breeding.
Pear anthracnose, caused by Colletotrichum fructicola, is a devastating disease that seriously affects most pear varieties, thereby compromising their yield and quality. However, effective control of this pathogen is lacking. Moreover, the critical resistance responses to C. fructicola in pear are unknown. To investigate these resistance mechanisms of pear against Colletotrichum fructicola, transcriptomic and metabolomic were performed and analyzed in pear anthracnose-resistant pear variety ‘Seli’ and the susceptible variety ‘Cuiguan’ after infection with C. fructicola, respectively. The differentially expressed genes and differentially accumulated metabolites (DAMs) were mainly related to metabolism and secondary metabolite synthetic pathways, including alpha-linoleic acid metabolism, phenylalanine biosynthesis metabolism, unsaturated fatty acids biosynthesis, and amino acids and derivatives biosynthesis etc. In particular, the accumulation of unsaturated fatty acids, amino acids and derivatives, such as linoleic acid and derivatives, lauric acid, N-acetyl-L-glutamic acid and L-proline was significantly increased in the resistant pear variety ‘Seli’ upon C. fructicola infection, while the amino acids of oxiglutatione and N-acetyl-L-glutamic acid, as well as the proanthocyanidins were significantly decreased in susceptible pear variety ‘Cuiguan’ upon C. fructicola infection, indicating that these metabolites were responsible for the different levels of resistance to anthracnose in ‘Seli’ and ‘Cuiguan’. Overall, our results provided new insights into pear anthracnose resistance regulation, and this may assist in developing new strategies to control pear anthracnose, as well as in breeding anthracnose-resistant varieties.
In the face of agricultural labor shortages, reducing labor and costs in rice production while meeting demand or increasing yield is crucial for sustainable agricultural development. Utilizing crop straw boards and high-density seedling raising can reduce labor demand and enhance rice yield. This study aimed to investigate the effects of seeding density and transplanting age on tillering patterns, panicle formation rates, and yield to determine optimal cultivation practices for maximizing rice yield. Two-year field experiments were conducted in Sihong County, China, using the japonica rice variety Nanjing 5718. Five seeding densities (150–350 g/tray) and four transplanting ages (10–25 days) were evaluated to assess their impact on tillering patterns, panicle formation rates, and yield. Innovative crop straw boards were employed to enhance planting efficiency and reduce dependence on seedling-raising soil. This approach also lessened tillage layer destruction, promoting sustainable practices. The results indicated that increasing seeding density significantly altered tillering and panicle formation patterns, reducing the occurrence and panicle formation rates of lower-position tillers. Although the occurrence of middle and high-position tillers increased, the overall number of panicles per hill decreased, especially at higher densities, negatively affecting yield. Reducing transplanting age promoted the emergence and panicle formation of lower-position tillers, mitigating these negative effects. Specifically, compared to traditional methods (150 g/tray, 20-day seedlings), the higher seeding density (300 g/tray) and shorter transplanting age (15-day seedlings) increased total panicle number by 3.79–4.73% and yield by 3.38–5.05%. Combining higher seeding densities with reduced transplanting ages offers significant advantages over conventional practices by enhancing resource utilization, improving tillering efficiency. These findings provide actionable recommendations for optimizing rice cultivation practices and contribute to sustainable agricultural development.