Genome-wide QTL mapping for stripe rust resistance in spring wheat line PI 660122 using the Wheat 15K SNP array.

Introduction: Stripe rust is a global disease of wheat. Identification of new resistance genes is key to developing and growing resistant varieties for control of the disease. Wheat line PI 660122 has exhibited a high level of stripe rust resistance for over a decade. However, the genetics of stripe rust resistance in this line has not been studied. A set of 239 recombinant inbred lines (RILs) was developed from a cross between PI 660122 and an elite Chinese cultivar Zhengmai 9023. Methods: The RIL population was phenotyped for stripe rust response in three field environments and genotyped with the Wheat 15K single-nucleotide polymorphism (SNP) array. Results: A total of nine quantitative trait loci (QTLs) for stripe rust resistance were mapped to chromosomes 1B (one QTL), 2B (one QTL), 4B (two QTLs), 4D (two QTLs), 6A (one QTL), 6D (one QTL), and 7D (one QTL), of which seven QTLs were stable and designated as QYrPI660122.swust-4BS, QYrPI660122.swust-4BL, QYrPI660122.swust-4DS, QYrPI660122.swust-4DL, QYrZM9023.swust-6AS, QYrZM9023.swust-6DS, and QYrPI660122.swust-7DS. QYrPI660122.swust-4DS was a major all-stage resistance QTL explaining the highest percentage (10.67%-20.97%) of the total phenotypic variation and was mapped to a 12.15-cM interval flanked by SNP markers AX-110046962 and AX-111093894 on chromosome 4DS. Discussion: The QTL and their linked SNP markers in this study can be used in wheat breeding to improve resistance to stripe rust. In addition, 26 lines were selected based on stripe rust resistance and agronomic traits in the field for further selection and release of new cultivars.

Spatial distribution characteristics of microplastics in the seawater column and sediments of the artificial reef area and adjacent water in Haizhou Bay.

Recently, scholars have been increasing concerned about microplastics (MPs). Unfortunately, information is lacking on the spatial distribution patterns of MPs in coastal seas; therefore, our understanding of the extent of offshore MP contamination remains incomplete. MP distribution in the seawater and surface sediments of an aquaculture area (AA), artificial reef area (AR), and comprehensive effect area (CEA) in Haizhou Bay were investigated in this study. The results showed that the mean abundances of MPs in the surface, middle and bottom seawater were 6.98 ± 3.01 n/m3, 9.12 ± 3.07 n/m3 and 10.20 ± 2.41 n/m3, respectively, and that the abundance in the sediment was 3.09 ± 1.16 n/g. The MP abundance in the bottom seawater was significantly higher than that in the surface seawater (P < 0.05). The correlation among MPs at different depths was not significant, but MPs in most habitats showed a significant correlation. We discovered a significant correlation between the abundance of MPs in the CEA seawater and AR sediments, but not between that in the CEA sediments and AR sediments. MPs can be transported from surface seawater to deeper layers by natural deposition processes. The horizontal transport of MPs due to the coastal gulf current and regular semidiurnal tides lead to the correlations observed in of MP abundance among the AA, CEA, and AR. Migration of MPs from the CEA to the AR was primarily caused by the southern eddies in Haizhou Bay, while migration of MPs from the sediment to the seawater could be due to upwelling in the AR. This was also the main reason there was a lack of a correlation between the sediment from the AR and the seawater from the CEA. This work provides a theoretical and empirical foundation for MP transport and source tracking.

Transfer of the high-temperature adult-plant stripe rust resistance gene Yr62 in four Chinese wheat cultivars.

Wheat stripe rust is one of the diseases that seriously affect wheat production worldwide. Breeding resistant cultivars is an effective way to control this disease. The wheat stripe rust resistance gene Yr62 has high-temperature adult-plant resistance (HTAP). In this study, PI 660,060, a single Yr62 gene line, was crossed with four Chinese wheat cultivars, LunXuan987 (LX987), Bainongaikang58 (AK58), ZhengMai9023 (ZM9023), and HanMai6172 (H6172). F1 seeds of four cross combinations were planted and self-crossed to develop the advance generations in the field. The seeds of each cross were mixed harvested and about 2400 to 3000 seeds were sown in each generation for F1 to F4 to maintain the maximum possible genotypes. Forty-five lines were selected and evaluated for resistance to stripe rust and agronomic traits, including plant height, number of grains per spike, and tiller number, in F5 and F6. Then, 33 lines with good agronomic traits and high disease resistance were developed to F9 generation. SSR markers Xgwm251 and Xgwm192 flank linked with the Yr62 were used to detect the presence of Yr62 in these 33 F9 lines. Of these, 22 lines were confirmed with the resistance gene Yr62. Finally, nine lines with good agronomic traits and disease resistance were successfully selected. The selected wheat lines in this study provide material support for the future breeding of wheat for stripe rust resistance. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-023-01393-1.

COMPARISON OF INTRAVITREAL INJECTION OF RANIBIZUMAB VERSUS LASER THERAPY FOR ZONE II TREATMENT-REQUIRING RETINOPATHY OF PREMATURITY.

PURPOSE: To compare the efficacy of intravitreal injection of ranibizumab (IVR) monotherapy and laser therapy for treatment-requiring retinopathy of prematurity (ROP) in Zone II. METHODS: A prospective, randomized, controlled single-center trial was applied from January 2014 to December 2014; infants who were diagnosed as Zone II treatment-requiring ROP (i.e., Zone II Stage 2 or 3 ROP with plus disease) were randomly assigned to receive IVR monotherapy or laser therapy, and the follow-up interval was at least 6 months. Any eyes that developed recurrence of ROP underwent crossover re-treatment. RESULTS: A total of 100 eyes of 50 ethnic Han Chinese infants were enrolled. At the last follow-up, 26 eyes of 13 infants developed recurrence of ROP in the IVR group and 2 eyes of 1 infant developed recurrence of ROP in the laser therapy group. There was a significant statistical difference in the rate of ROP recurrence between IVR and laser therapy to treat Zone II treatment-requiring ROP (P = 0.001). CONCLUSION: Although IVR appears to regress ROP to certain levels and continue to promote the vascularization of peripheral retinal vessels, a substantial proportion of infants developed recurrence of ROP after a single-dose IVR. Therefore, IVR is not recommended as a single-dose monotherapy for Zone II treatment-requiring ROP.

[The clinical study on intravitreous injection of ranibizumab for aggressive posterior retinopathy of prematurity].

OBJECTIVE: To observe the retinal vascular development and changes on aggressive posterior retinopathy of prematurity (AP-ROP) by intravitreal ranibizumab, evaluate the therapeutic effect, and provide the basis for clinical treatment. METHODS: The total of 38 eyes of 19 premature infants who were diagnosed as AP-ROP from January 2012 to October 2013 in our hospital were performed intravitreal injection of ranibizumab (0.04 ml). It was observed about the regression of plus diseases, ridges, neovascularization on the ridge and the development of peripheral retinal vessel. Laser photocoagulation were performed for 14 eyes of 7 cases whose plus diseases, ridges and neovascularization on the ridge didn't regress completely after intralvitreal injection of ranibizumab. RESULTS: All infants were found retinopathy regressed and retinal vessels continued to develop peripherally to some degree. Of all infants, 24 eyes of 12 infants were found complete regression of retinopathy, resolution of neovascularization and bleeding and that retinal vessels continued to develop to ora serrata or scarification of peripheral retinopathy. Fourteen eyes of 7 infants were found retinopathy didn't regressed completely and regressed completely after combing intravitreal ranibizumab injection. All 19 infants didn't occure infection, ocular or systemic complications. CONCLUSIONS: The efficacy of intravitreal injection of ranibizumab is good for AP-ROP. It can made ridge, neovascularization on the ridge and plus disease regress, as well as let the retinal vessel continue development. Infants with no regressed retinopathy may need combined laser photocoagulation.