The low egg production of goose greatly limits the development of the industry. China possesses the most abundant goose breeds resources. In this study, genome resequencing data of swan goose (Anser cygnoides) and domesticated high and low laying goose breeds (Anser cygnoides domestiation) were used to identify key genes related to egg laying ability in geese and verify their functions. Selective sweep analyses revealed 416 genes that were specifically selected during the domestication process from swan geese to high laying geese. Furthermore, SNPs and Indels markers were used in GWAS analyses between high and low laying breed geese. The results showed that RTCB, BPIFC, SYN3, SYNE1, VIP, and ESR1 may be related to the differences in laying ability of geese. Notably, only ESR1 was identified simultaneously by GWAS and selective sweep analysis. The genotype of Indelchr3:54429172, located downstream of ESR1, was confirmed to affect the expression of ESR1 in the ovarian stroma and showed significant correlation with body weight at first egg and laying frequency of geese. CCK-8, EdU, and flow cytometry confirmed that ESR1 can promote the apoptosis of goose pre-hierarchical follicles ganulosa cells (phGCs) and inhibit their proliferation. Combined with transcriptome data, it was found ESR1 involved in the function of goose phGCs may be related to MAPK and TGF-beta signaling pathways. Overall, our study used genomic information from different goose breeds to identify an indel located in the downstream of ESR1 associated with goose laying ability. The main pathways and biological processes of ESR1 involved in the regulation of goose laying ability were identified by cell biology and transcriptomics methods. These results are helpful to further understand the laying ability characteristics of goose and improve the egg production of geese.
Population growth and growing demand for livestock products produce large amounts of manure, which can be harnessed to maintain soil sustainability and crop productivity. However, the impacts of excessive manure application on crop yields, nitrogen (N)-cycling processes and microorganisms remain unknown. Here, we explored the effects of 20-year of excessive rates (18 and 27 Mg ha–1 yr–1) of pig manure application on peanut crop yields, soil nutrient contents, N-cycling processes and the abundance of N-cycling microorganisms in an acidic Ultisol in summer and winter, compared with none and a regular rate (9 Mg ha–1 yr–1) of pig manure application. Long-term excessive pig manure application, especially at the high-rate, significantly increased soil nutrient contents, the abundance of N-cycling functional genes, potential nitrification and denitrification activity, while it had a weaker effect on peanut yield and plant biomass. Compared with manure application, seasonality had a much weaker effect on N-cycling gene abundance. Random forest analysis showed that available phosphorus (AP) content was the primary predictor for N-cycling gene abundance, with significant and positive associations with all tested N-cycling genes. Our study clearly illustrated that excessive manure application would increase N-cycling gene abundance and potential N loss with relatively weak promotion of crop yields, providing significant implications for sustainable agriculture in the acidic Ultisols.
Targeted mutations of BnPAP2 lead to a yellow seed coat in Brassica napus L.
Straw return increases crop production by improving soil organic carbon sequestration and soil aggregation in a long-term wheat–cotton cropping system
Straw return is a promising strategy for managing soil organic carbon (SOC) and improving yield stability. However, the optimal straw return strategy for sustainable crop production in the wheat (Triticum aestivum L.)–cotton (Gossypium hirsutum L.) cropping system remains uncertain. The objective of this study was to quantify the long-term (10 years) impact of carbon (C) input on SOC sequestration, soil aggregation and crop yields in a wheat–cotton cropping system in the Yangtze River Valley, China. Five treatments were arranged with a single-factor randomized design as follows: no straw return (Control), return of wheat straw only (Wt), return of cotton straw only (Ct), return of 50% wheat and 50% cotton straw (Wh-Ch) and return of 100% wheat and 100% cotton straw (Wt-Ct). In comparison to the Control, the SOC content increased by 8.4 to 20.2% under straw return. A significant linear positive correlation between SOC sequestration and C input (1.42–7.19 Mg ha−1 yr−1) (P<0.05) was detected. The percentages of aggregates of sizes >2 and 1–2 mm at the 0–20 cm soil depth were also significantly elevated under straw return, with the greatest increase of the aggregate stability in the Wt-Ct treatment (28.1%). The average wheat yields increased by 12.4–36.0% and cotton yields increased by 29.4–73.7%, and significantly linear positive correlations were also detected between C input and the yields of wheat and cotton. The average sustainable yield index (SYI) reached a maximum value of 0.69 when the C input was 7.08 Mg ha−1 yr−1, which was close to the maximum value (SYI of 0.69, C input of 7.19 Mg ha−1 yr–1) in the Wt-Ct treatment. Overall, the return of both wheat and cotton straw was the best strategy for improving SOC sequestration, soil aggregation, yields and their sustainability in the wheat–cotton rotation system.
Denitrification-induced nitrogen (N) losses from croplands may be greatly increased by intensive fertilization. However, the accurate quantification of these losses is still challenging due to insufficient available in situ measurements of soil dinitrogen (N2) emissions. We carried out two one-week experiments in a maize–wheat cropping system with calcareous soil using the 15N gas-flux (15NGF) method to measure in situ N2 fluxes following urea application. Applications of 15N-labeled urea (99 atom%, 130–150 kg N ha−1) were followed by irrigation on the 1st, 3rd, and 5th days after fertilization (DAF 1, 3, and 5, respectively). The detection limits of the soil N2 fluxes were 163–1 565, 81–485, and 54–281 μg N m−2 h−1 for the two-, four-, and six-hour static chamber enclosures, respectively. The N2 fluxes measured in 120 cases varied between 159 and 2 943 (811 on average) μg N m−2 h−1, which were higher than the detection limits, with the exception of only two cases. The N2 fluxes at DAF 3 were significantly higher (by nearly 80% (P<0.01)) than those at DAF 1 and 5 in the maize experiment, while there were no significant differences among the irrigation times in the wheat experiment. The N2 fluxes and the ratios of nitrous oxide (N2O) to the N2O plus N2 fluxes following urea application to maize were approximately 65% and 11 times larger, respectively (P<0.01), than those following urea application to wheat. Such differences could be mainly attributed to the higher soil water contents, temperatures, and availability of soil N substrates in the maize experiment than in the wheat experiment. This study suggests that the 15NGF method is sensitive enough to measure in situ N2 fluxes from intensively fertilized croplands with calcareous soils.
As a multifunctional crop, rapeseed provides vegetables by picking shoots. Shoot removal reduced yield, while nitrogen (N) application results in efficiency gains. However, the effect of N rate on pod growth, N use efficiency (NUE) and seed yield after shoot removal is unclear. A 2-year field experiment was set with four N rates (0 [N0], 90 [N1], 180 [N2], and 270 [N3] kg ha-1) and two shoot treatments (no shoot removal [CK], shoot removal [SR]). Results showed the shoot removal decreased population biomass (PB) at maturity across all N levels. Conversely, N application increased the PB after shoot removal and elevated soluble sugar and protein in shoots. Shoot removal increased the seeds per pod (13.5-26.9%), reduced the pods per plant (33.1-45.8%) and population seed yield (19.5-38.4%). N application effectively increased the yield related index, and led to an increase in population seed yield by 187.2 - 465.0% in the CK group, and by 185.6 - 430.7% in the SR group. Moreover, the seed yield reached its maximum under the N3 in both groups. The leaf N content per area (Na) and net photosynthetic rate (Pn) were increased, but leaf photosynthetic N use efficiency (PNUE) were decreased at 20 days after shoot removal, which lead to a significant decrease in N use efficiency(NUE). N supply increased the plant organ N content and PB, but decreased the NUE at maturity stage. Pn of the pod wall at 25 days after flowering was elevated due to its optimized chloroplasts ultrastructure and increased rubisco and sucrose synthase activities under shoot removal and more N. However, the greater amino acid/soluble sugar ratio (A/S) of the pod wall significantly increased the seed protein content and decreased the oil content. Though the oil yield was reduced by 63.8-71.0% under SR×N3 treatment compared with CK×N3, it was comparable to that of CK with 90 kg N ha-1 treatment. The results indicated that N applying improves the carbon metabolism of the pod wall and alleviates yield reduction after shoot removal but reduces NUE and seed oil content of rapeseed. The findings guide the balancing of rapeseed’s vegetable and oil production, and optimize N fertilization for sustainable, efficient rapeseed farming.