Objectives: To provide insights for breeding high-quality rice varieties, we analyzed local rice (Oryza sativa L.) germplasm from Yunnan Province, China, focusing on the relationships among Waxy gene alleles, indica–japonica differentiation, and amylose content (AC). Methods: We examined 201 local rice accessions. Two functional molecular markers for the Waxy gene were used to detect four alleles (Wx^a, Wx^b, Wxⁱⁿ, Wx^mw). Additionally, 33 InDel markers were employed to classify indica–japonica attributes, and AC was measured according to GB/T 15683-2008. Results: We detected 175 accessions with Wx^a, 20 with Wx^b, 4 with Wxⁱⁿ, and 2 with Wx^mw, indicating Wx^a dominance and a diverse genetic basis at the Waxy locus. Indica–japonica classification identified 180 indica-type, 19 japonica-type, and 2 intermediate-type accessions, confirming predominant indica differentiation in Yunnan rice. Integrating Waxy allele detection, indica–japonica attributes, and AC showed that Wx^a occurred primarily in indica rice with higher AC (mean 22.55%), comparable to Wxⁱⁿ (mean 24.33%); Wx^b was mainly found in japonica rice with lower AC (mean 13.46%), similar to Wx^mw (mean 15.65%). Conclusions: Local Yunnan rice exhibits Wx^a predominance at the Waxy locus and clear indica differentiation. The observed associations between Waxy alleles, subspecies attributes, and AC provide useful references for marker-assisted breeding of premium rice and for exploiting indica–japonica heterosis.

Great progress has been achieved in the field of protection of new varieties of plants since Ministry of Agriculture established the PVP (Plant Variety Protection) system in 1999, which could be witnessed by the annually increased application for PVP. However, how to raise the efficiency of PVP examination to meet the growing demand of application has become a burning problem. In this paper, we analyzed the current situation and existing problems of PVP information processing in China. Based on IT and internet technology, we proposed a platform of PVP Information System, introduced the overall framework of PVP Information System and corresponding constituent modules, gave an account of the key techniques of security management and data integration in constructing this system. While affirming the significance of the PVP Information System in speeding up the PVP examination, strengthening the protection of agricultural intellectual property, and better serving the technology innovation, the existing problems were also pointed out for the safe and effective operation.

Biological control is an effective and environmentally friendly strategy for managing plant diseases. In this study, a broad-spectrum antagonistic bacterium, designated strain AN6, was isolated from rice plants and exhibited potent inhibitory activity against a variety of phytopathogens. In Oxford cup assays, AN6 suppressed the growth of Xanthomonas oryzae pv. oryzae (Xoo) by 73.60%, and its cell-free culture filtrate caused pronounced morphological deformation in the bacterial cells. Further in vitro assays, including dual-culture assays, volatile organic compound (VOC) assays, and cell-free supernatant (CFS) assays, demonstrated that AN6 also exerted strong antifungal effects against several pathogenic fungi. In addition, the strain was found to produce proteases and siderophores, which may contribute to its antagonistic capabilities. Taxonomic identification based on morphological traits, 16S rRNA and gyrA gene sequencing, average nucleotide identity (ANI), in silico DNA–DNA hybridization (isDDH), and phylogenetic analysis classified strain AN6 as Bacillus velezensis. Whole-genome sequencing revealed that AN6 harbors a 3,929,788 bp genome comprising 4025 protein-coding genes with a GC content of 46.50%. Thirteen biosynthetic gene clusters (BGCs) associated with the production of secondary metabolites—such as nonribosomal peptides, polyketides, and dipeptide antibiotics—were identified. The pot experiment further validated the biocontrol potential of AN6, achieving an 80.49% reduction in rice bacterial blight caused by Xanthomonas oryzae pv. oryzae. Collectively, these results indicate that B. velezensis AN6 is a promising candidate for development as a highly effective biocontrol agent for the integrated management of diverse plant diseases.

Strains from the genus of Pectobacterium can cause soft rot in numerous important plants, leading to significant losses. 16S rRNA gene sequences reliably identify genera, but species identification is sometimes challenging due to indistinguishable species or strains and unrecognized new taxa. Therefore, a dependable and straightforward classification method is needed. In this study, we analyzed the complete genome sequence and predicted genome components of Pectobacterium strains. We also assessed their genetic relationships using average nucleotide identity and in silico DNA–DNA hybridization, alongside phylogenetic analysis. This was done by examining the whole-genome sequences of 14 new strains isolated in our laboratory, responsible for plant soft rot, and comparing them with 64 strains’ genome sequences available in GenBank. The results reveal that three subspecies of P. carotovorum with genome sequences deposited in GenBank (PccS1, PCC21, and strain 67) need to be reclassified as separate species and also confirm that our new isolated strains are accurately categorized at the species level. Additionally, the virulence and adaptability of certain strains of Pectobacterium (PccS1, SCRI1043, and SCC3193) are influenced by horizontal acquisition genes. Furthermore, our findings suggest that the diversity in the car gene cluster among Pectobacterium strains likely stems from gene losing, as well as the auto-induced regulatory mechanisms underlying virulence determinant gene activation, and Car biosynthesis might act in different ways in PccS1, enhancing our knowledge of their genomic traits through comparative studies.

Two-line hybrid rice breeding relies on photoperiod-/thermosensitive genic male sterile (P/TGMS) lines with reliable fertility transition across different environments. The fertility of japonica P/TGMS lines is intricately regulated by photoperiod and temperature, making it more challenging to breed japonica sterile lines with stable sterility than indica sterile lines. This complexity is one of the primary reasons the breeding and promotion of two-line japonica hybrid rice has lagged behind that of indica hybrid rice. Here, we report on Yun1032S, a novel japonica P/TGMS line bred in the low-latitude plateau. It was bred by crossing Peiai 64S, the famous P/TGMS line with the largest application area in China, with Yungengyou 1, a plateau japonica variety noted for its excellent cold tolerance and disease resistance. Yun1032S exhibited stable sterility and female-parent traits favorable for two-line seed production. The elite combination YLY7706 (Yunliangyou7706), derived from a cross between Yun1032S and Yungenghui7501, showed a stable and competitive yield and strong disease resistance in the 2022–2023 Yunnan provincial regional trials. To analyze the genetic basis of phenotypes, we performed whole-genome resequencing and functional loci analysis of the parents and found that they carry a great number of superior alleles, which account for their yield and disease-resistant performance. To assess the breeding value of Yun1032S, we analyzed heterosis of a new batch of combinations derived from Yun1032S and identified a new combination, Jian3, with greater yield potential than YLY7706. These findings not only enhance the breeding of japonica P/TGMS lines but also provide direction for future pairing of two-line hybrid combination breeding. The study presents innovative concepts that further integrate genomics with traditional breeding techniques. Ultimately, Yun1032S marks a significant milestone in japonica P/TGMS line breeding technology, opening new avenues for the development of the two-line system.