The creation of herbicide-resistant rice germplasm is essential for breeding new herbicide-resistant rice varieties. By using CRISPR/Cas9 gene editing technology, the acetyl-CoA carboxylase OsACC1 gene was edited with the sterile line An 9S as the material, and a two-line sterile rice germplasm with herbicide resistance was created.

By using CRISPR/Cas9 technology, a single-base mutation vector, ePE2-ACC-I1879V, was constructed with acetyl-CoA carboxylase OsACC1 as the target gene. With An 9S as the transformation material, transgenic plants were obtained by Agrobacterium-mediated transformation. The genotypes and phenotypes were identified by sequencing the mutation sites of transgenic plants, conducting herbicide spraying tests and agronomic traits analysis.

Twenty-four ACC1^I1879V mutant plants were obtained as confirmed by molecular detection in T₀ generation; A total of 96 homozygous mutant plants were obtained from 24 lines in the T₁ generation through segregation and screening, all of which had herbicide resistance. High-throughput sequencing showed that the three tested lines (NS512, NS513, NS514) contained no exogenous transgenic elements. Furthermore, the survival rate after spraying with 4% haloxyfop-P-methyl was 100%. Compared with the control An 9S, the NS512 line had increased plant height and wider flag leaf; the NS513 line had increased plant height and longer and wider flag leaf; and the NS514 line had a narrower flag leaf; the fertility of the three tested lines remained unchanged, and there was no significant difference in the number of effective panicles per plant and the panicle length. The transgenic safety evaluation indicated that the OsACC1 protein shares no sequence similarity with any known toxic proteins, antinutritional factors or allergens. Therefore, it is considered safe for human consumption.

Using CRISPR/Cas9 gene editing technology, we obtained homozygous mutant lines that are resistant to ACCase inhibitor herbicides. These lines are genetically stable, free of transgenic components, exhibit unaltered fertility, and are safe, providing fundamental materials for herbicide-resistant breeding in rice.

Fragrance is an important trait of rice eating quality. In this study, the fragrance gene Badh2 in rice was edited using CRISPR/Cas9 technology to create a high-quality aromatic japonica rice line.

Two target sequences located in the third and fourth exons of Badh2 were selected as target sites for constructing the binary expression vector pHUE411-Badh2-gRNA. The high-quality japonica rice line Tai 20-29 was used as the transformation material.

Twenty T0 transgenic plants were obtained after transformation. Through propagation, PCR, and sequencing verification, six homozygous mutants with different base alterations in the third and fourth exons of Badh2 were identified. Except for a slightly lower seed setting rate and a higher grain number per panicle, the six mutants(bh62, bh64, bh65, bh67, bh68, and bh74) showed similar agronomic traits such as panicle length, grain length, grain width, and 1000-grain weight compared with the wild-type Tai 20-29. The mutants showed a significantly lower seed setting rate and a higher grain number per panicle compared to Tai 20-29. The 2-AP content in brown rice of mutants bh62, bh64, bh65, and the wild type was determined by GC-MS. The results showed that the 2-AP content in the mutants increased significantly, reaching 24.27, 33.89, and 38.96 mg/kg, respectively, which was much higher than that in Tai 20-29.

We successfully generated a high-quality aromatic japonica rice line by editing the Badh2 gene using CRISPR/Cas9 technology.

Developing stable, efficient, and reliable markers for purity testing of three-line hybrid seeds is crucial for current hybrid rice seed production.

Based on the specific sequences of the wild abortive-type sterility gene WA352, the major fertility-restoring gene Rf4, and the internal reference gene Actin, multiple single-gene detection markers were designed. PCR amplification was then performed by optimizing the primer mixture ratio.

A mixture of primers WA352-2, Rf4-3, and Actin-3 in a ratio of 1:11:3 enabled simultaneous detection of the genotypes of WA352, Rf4, and Actin in a single PCR reaction, allowing differentiation among wild abortive-type CMS lines, restorer lines, maintainer lines, and hybrids.

The detection method established in this study is simple to perform and yields stable and reliable results. It can not only identify genotypes in wild-abortive three-line rice but also serve as an effective tool for molecular marker-assisted breeding. By improving the accuracy of purity assessment during breeding, this method provides strong support for achieving high-yield and high-quality rice breeding objectives in China.

To clarify the effects of rice planting methods and fertilization on root morphology, growth and development, and yield formation, and to provide a theoretical basis for rice cultivation and scientific fertilization.

A two-factor experimental design was employed to investigate the effects of planting method (direct seeding and transplanting) and fertilization (no fertilization and fertilization) on root distribution, root morphology, root vigor, and lodging resistance in rice. The hybrid rice Heliangyou 332 (HLY332) and conventional rice Huanghuazhan (HHZ) were used as experimental materials.

(1) Compared with no fertilization, fertilization significantly increased yield by 15.3% and 15.0% under direct seeding and transplanting conditions for HLY332, and by 18.6% and 22.1% for HHZ, respectively. No significant yield difference was detected between planting methods for either variety. (2) In direct-seeded rice, roots were mainly distributed in the 0-5 cm soil layer. The average root biomass proportion in the 0-5 cm layer under no-fertilizer and fertilizer treatments was 50.1% and 56.8% for HLY332, and 63.5% and 67.0% for HHZ, respectively. In contrast, transplanted rice concentrated roots in the 5-10 cm layer, with proportions of 42.9% and 41.9% for HLY332, and 53.2% and 49.1% for HHZ, respectively. Fertilization increased total root biomass by 46.9% and 45.9% under direct seeding and transplanting for HLY332, and by 64.9% and 56.9% for HHZ, compared to no fertilization. Root bleeding intensity was significantly enhanced by fertilization, with increases of 113.3% and 110.6% for HLY332, and 46.1% and 60.8% for HHZ under direct seeding and transplanting, respectively. (3) Compared with direct seeding, transplanting significantly improved bending resistance. Bending resistance was increased by 23.9% and 15.2% in HLY332 under no-fertilizer and fertilized conditions, and by 12.5% and 17.0% in HHZ, respectively. Fertilization also enhanced bending resistance, with increases of 25.5% and 16.8% for HLY332 under direct seeding and transplanting, and 23.7% and 28.6% for HHZ under transplanting, relative to no fertilization.

The distinct vertical distribution of roots in the soil profile is a key trait differentiating direct-seeded and transplanted rice. Under the conditions of this study, fertilization significantly improved root morphology and increased grain yield in both planting methods, with no significant yield difference between direct seeding and transplanting. Therefore, integrating direct seeding with scientific fertilization represents a viable approach to meet the growing demand for light and simplified cultivation in rice production.

The continuous cropping system in mixed single- and double-season rice areas provides an uninterrupted food supply for the overwintering and subsequent 2-3 generations of Chilo suppressalis (Walker), leading to increased pest populations and more severe crop damage. This study aimed to evaluate the control efficacy of an intelligent active aerosol dispenser for mating disruption against C. suppressalis in early and late rice.

A mating disruption plot and a farmer-managed control plot were established in a mixed single- and double-season rice area in Sanjie Town, Shengzhou, Zhejiang Province. On April 12, 2024 (eight days before rice transplanting), intelligent active aerosol dispensers were deployed in the mating disruption area. High doses of sex pheromone were released continuously during both early and late rice seasons to disrupt the mating behavior of C. suppressalis. Field surveys were conducted to monitor moth catches in pheromone traps, the percentage of damaged plants, and larval density. Natural enemies were sampled using malaise traps and suction samplers during the early and late rice seasons, respectively.

The mating disruption efficacy on C. suppressalis adults was 94.1% ± 0.02% for the overwintering generation, 78.6% ± 12.7% for the first generation, and 87.3% ± 0.01% for the second generation. The disrupted rates for non-target pests were 85.6% ± 0.07% for Sesamia inferens (Walker) in early rice and 79.2% ± 0.07% for Cnaphalocrocis medinalis Guenée in late rice. During the early rice season, the technology reduced larval density of C. suppressalis by 71.5%-83.3% and the percentage of damaged plants by 59.4%-74.5%. Although natural enemy abundance did not differ significantly, the beneficial-to-pest ratio was markedly higher in the mating disruption plot (2470.6% ± 594.5%) than in the control plot (148.8% ± 38.4%). In the late rice season, larval density and plant damage of C. suppressalis were reduced by 80.7%-90.9% and 61.2%-89.6%, respectively, while the leaf rolling rate caused by C. medinalis decreased by 63.7%. Again, natural enemy populations showed no significant difference, but the beneficial-to-pest ratio was higher in the mating disruption area (333.3% ± 91.3%) than in the control (64.2% ± 24.9%).

The intelligent active aerosol dispenser effectively suppressed the larval population of C. suppressalis and reduced crop damage in the mixed cropping rice area. It also demonstrated significant control effects against S. inferens and C. medinalis. Furthermore, the technology had no adverse impact on natural enemy populations and resulted in a higher beneficial-to-pest ratio compared to conventional farmer practice.

This study aimed to investigate the feeding and damage characteristics of Pomacea canaliculata on direct-seeded rice seedlings of different varieties, and to provide a theoretical basis for effective control of P. canaliculata in direct-seeding rice fields.

Laboratory experiments were conducted to examine the feeding and damage behavior of different sizes of P. canaliculata—small snails (0.51 g), medium snails (4.37 g), and large snails (7.82 g)—on direct-seeded rice seedlings of three varieties, Yongyou 1540 (indica-japonica hybrid), Xiushui 134 (japonica), and Zhongzao 39 (indica).

The damage period caused by small snails to direct-seeded rice seedlings of different varieties was 7 days, with the peak damage occurring 1-4 days after seeding. For medium and large snails, the damage period lasted about 21 days, with the peak occurring 1-10 days after seeding. The daily damage rates caused by small, medium, and large snails reached 1.9-2.6, 9.2-12.1, and 16.2-23.1 seedlings per day, respectively. The feeding amount of large snails was 22.3-30.1 times that of small snails and 1.7-1.9 times that of medium snails, while the feeding amount of medium snails was 11.5-18.3 times that of small snails.

Pomacea canaliculata caused damage to direct-seeded rice seedlings for approximately 21 days, with the peak damage occurring within 10 days after seeding. Small snails caused relatively minor harm, whereas medium and large snails were the main damaging agents. Feeding damage by P. canaliculata was highest on indica rice, followed by indica-japonica hybrid rice, and lowest on japonica rice. Based on these feeding and damage characteristics, targeted control measures against P. canaliculata are proposed.

This study aims to elucidate the function and mechanism of the ERF transcription factor OsERF93 in rice sheath blight resistance, providing genetic resources for disease-resistant breeding.

The expression pattern, transcriptional regulatory function, and subcellular localization of OsERF93 were analyzed using RT-qPCR and transcriptional activation assays in rice protoplasts. Transgenic overexpression and knockout lines were constructed to investigate the role of OsERF93 in sheath blight resistance. Expression differences of salicylic acid (SA), jasmonic acid (JA), and ethylene (ET)-related signaling genes were compared before and after inoculation in transgenic lines. Additionally, agronomic traits of overexpression lines and controls were evaluated.

OsERF93 was highly expressed in rice leaves and leaf sheaths and induced by sheath blight fungus infection. The encoded protein localized to the nucleus and cell membrane, exhibiting transcriptional activation activity. Overexpression of OsERF93 significantly enhanced sheath blight resistance, while knockout lines showed reduced resistance. JA biosynthesis gene OsAOS2 and certain PR genes were upregulated in overexpression lines and downregulated in knockout lines. Overexpression lines exhibited slightly reduced plant height and thousand-grain weight compared to wild-type controls but had significantly higher grain number per panicle. No significant differences were observed in tiller number, primary branch number, and panicle length between overexpression lines and controls.

The results indicate that OsERF93 positively regulates rice sheath blight resistance by activating the jasmonic acid signaling pathway, offering a novel genetic resource for rice disease-resistant breeding.