摘要：
INTRODUCTION: In recent years, with the rapid expansion of ratoon rice production in Hunan, a unique ratoon rice-based production system, forage-grain ratoon rice (FG-RR), has been newly developed. Ratooning rice is a season of rice harvested by utilizing the dormant buds on the rice stubble left after harvesting the first season of rice to sprout and grow. Therefore, the characteristics of stalks themselves are crucial for the production of ratoon rice. The cutting period and higher stubble height directly affect the characteristics of ratoon rice stubbles. Based on this, we conducted the following research. METHODS: In 2021 and 2022, field experiments were conducted in central China to study the effects of different cutting periods and stubble height on the regeneration rate and nutrient content of ratoon crops. The treatments included two cutting periods (10 days after heading in the first season and 30 days after heading in the first season, respectively referred to as T10 and T30) and two stubble heights (10 cm and 30 cm, respectively referred to as H10 and H30). RESULTS: Compared with the T30H30 treatment, T10H10 and T10H30 increased grain yield by 48.1%, 41.7%, 73.1%, and 65.2% in the two-year ratoon seasons, while T30H10 reduced grain yield by 30.9% and 19.5% in the two years, respectively. Early cutting increased the panicles, spikelets per panicle, and filled grain rate to varying increase, while higher stubble height increased panicles but decreased spikelet panicle. On the one hand, early cutting and higher stubble height increased the dry and fresh weight, nonstructural carbohydrates (NSCs), organic carbon (C), and nitrogen content of rice stalks, thereby improving the regeneration rate of ratoon rice. On the other hand, early cutting and higher stubble height retention increased the accumulation of nitrogen in rice stubble throughout the entire growth period and facilitated the transport of nitrogen to the mature panicles. DISCUSSION: Therefore, appropriate early cutting and higher stubble height retention are the keys to improving the grain yield and stability of ratoon rice.
作者机构：
[Tang, Qiyuan; Song, Linqiong; Wang, Weiqin; He, Hui] College of Agronomy, Hunan Agricultural University, Changsha, 410128, China;[Zheng, Huabin] College of Agronomy, Hunan Agricultural University, Changsha, 410128, China. hbzheng@hunau.edu.cn
关键词：
Large-panicle cultivars;Main season;Ratoon season
摘要：
Ratoon rice is considered an eco-friendly and resource-efficient method for rice cultivation, providing innovative strategies to mitigate the global food crisis. To clarify the critical yield components for achieving high annual grain yield in ratoon rice, data from 136 widely cultivated rice cultivars were collected through a six-year field experiment. The study analyzed the correlations between yield components and yields for both the main season and the ratoon season, indicating that main yields vary between 5.9 and 10.9 Mg ha(-1), exhibiting a highly significant positive correlation with spikelets per panicle; ratoon yields range from 1.8 to 7.1 Mg ha(-1), showing a highly significant positive correlation with panicles per m(2), grain filling rate, and 1000-grain weight. Path analysis reveals that, in terms of contributing to ratoon yield, the grain filling rate is the most influential component, followed by panicles per m(2), and 1000-grain weight. Therefore, by selecting large-panicle cultivars in the main season and enhancing panicles per m(2), grain filling rate, and grain weight in the ratoon season, high annual yield in ratoon rice can be realized.
关键词：
rice;Seed priming;Seed deterioration;Priming methods;Reactive Oxygen Species
摘要：
<jats:sec><jats:title>Introduction</jats:title><jats:p>Seed priming is a pre-sowing seed treatment that is beneficial for rice seed germination and seedling growth, but the reduced seed longevity after seed priming greatly limited its adoption. The deterioration of primed seeds showed large differences among different studies, and the priming method might play an important role in regulating the deterioration speed of primed seeds. However, whether and how the priming method affected the deterioration of primed rice seeds during storage remains unknown. </jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>In this study, two typical seed priming methods, namely hydropriming (HP) and osmopriming (PEG) were compared under artificially accelerated aging conditions, the changes in germination performance, starch metabolism, seed respiration and reactive oxygen species accumulation before and after accelerated aging were determined.</jats:p></jats:sec><jats:sec><jats:title>Results and discussion</jats:title><jats:p>Hydroprimed rice seeds exhibited significantly faster deterioration speed than that of PEG-primed seeds in terms of germination speed and percentage. Meanwhile, α-amylase activity and total soluble sugar content in hydroprimed seeds were reduced by 19.3% and 10.0% respectively after aging, as compared with PEG-primed seeds. Such effects were strongly associated with the increased reactive oxygen generation and lipid peroxidation, as the content of superoxide anion, hydrogen peroxide and malondialdehyde in hydroprimed seeds were 4.4%, 12.3% and 13.7% higher than those in PEG-primed seeds after aging, such effect could be attributed to the increased respiratory metabolism in hydroprimed seeds. In addition, the simultaneous use of N-acetylcysteine with HP and PEG priming greatly inhibited the deterioration of primed rice seeds, suggesting that the ability to scavenge reactive oxygen species may be the key factor affecting the speed of deterioration in primed rice seeds during storage.</jats:p></jats:sec>
期刊：
Crop and Environment,2023年2(3):101-110 ISSN：2773-126X
通讯作者：
Qiyuan Tang
作者机构：
[Weiqin Wang; Huabin Zheng; Yuanwei Chen; Dan Zou; Youyi Luo; Qiyuan Tang] College of Agronomy, Hunan Agricultural University, Changsha, Hunan 410128, China
通讯机构：
[Qiyuan Tang] C;College of Agronomy, Hunan Agricultural University, Changsha, Hunan 410128, China
关键词：
Cultivation technology;Hunan Province;Mechanical harvesting;Ratoon rice;Rice production
摘要：
As the largest rice production province in China, the ratoon rice in Hunan has rapidly developed in recent years in the aspects of planting area, total production, and cultivation technologies. The present review is undertaken to summarize the past and current status and the key practices of ratoon rice production in Hunan. The planting area of ratoon rice in Hunan was 267,000 ha in 2019, with the average yield of 7.50–10.50 t ha−1 and 2.30–6.00 t ha−1 in the main and ratoon seasons, respectively. The grain quality in ratoon season is similar to or even better than that of late-season rice, but the relatively poor grain quality in the main season limits the profits for farmers. In recent years, research on the cultivation technology of ratoon rice has been widely conducted in Hunan, which led to the development of a series of key practices for ratoon rice production with regard to variety selection, sowing dates, crop establishment, fertilizer and water management, straw cutting height and harvesting time, and the controls of pests, diseases, and abiotic stresses. However, the constraints in policy intervention, as well as the large yield gap, have greatly limited the further expansion of ratoon rice in Hunan. To further promote ratoon rice production in Hunan, the innovation and extension of fully mechanized ratoon rice cultivation technologies, breeding and chemical regulation approaches to enhance ratooning ability, and support from the local government regarding policy, infrastructure, demonstration, and training must be strengthened in the future.
摘要：
<jats:title>Abstract</jats:title><jats:p>In present study, sodium salt of α-naphthalene acetic acid (NA), potassium salt of fulvic acid (KF) and their combinations were applied to the growth substrates of tomato seedlings (<jats:italic>Solanum lycopersicum</jats:italic> L.) under chilling stress. The changes in aboveground biomass, root attributes, pigment contents, chlorophyll fluorescence, photosynthesis, osmotic regulation substances, and antioxidant enzymes activity of the tomato seedlings in response to NA and KF were investigated. The application of NA, KF and their combination could promote the growth of plant height and stem diameter of tomato seedlings under chilling stress to varying degrees, and improve root characteristics by increasing root volume, root length and root activity, and increase dry matter accumulation. In addition, the combined use of NA and KF improved the seedling leaf chlorophyll content, qP, Fv/Fm, ΦPSII , Pn and increased the activity of antioxidant enzymes in the tomato plants. The above results suggested a synergistic effect between NA and KF to stimulate the seedlings growth and to enhance the ROS scavenging ability of tomato, which has never been reported in previous research before. However, further researches are needed to explore the physiological and molecular mechanism underlying the synergistic effect between NA and KF. </jats:p>
通讯机构：
[Huabin Zheng; Qiyuan Tang] C;College of Agronomy Hunan Agricultural University, Changsha 410128, PR China<&wdkj&>Collaborative Innovation Center for Grain and Oil Crop in Southern Paddy Field, Changsha 410128, PR China
摘要：
Forage-food dual-purpose ratoon rice cropping (FFRR) is used to balance forage demands with ratoon rice grain yields, that is whole plant (stem and sheath, panicles) cuttings in the main season are used as forage, and rice in the regeneration season is used as food. In this study, the local ratoon rice production system as the control, we were carried out the field experiment of cultivation practices (cutting time and cutting height), and investigated the system productivity, economic benefits, carbon footprints and energy use efficiency. The energy use efficiency, energy productivity and energy profitability increased with cutting time delay, and cutting height decreased. Significant differences of these index were observed among the treatments for cutting time and cutting height (p < 0.05). Carbon efficiency and carbon sustainability index was in-crease with cutting time delay, and there was significant difference among the treatment of cutting time in 2018 (p < 0.05), the minimum carbon footprint of FFRR was 78.6 kgCO2 t-1 averagely at the cutting time of 30 days after the flowering stage. In 2018, the maximum net income of FFRR was 30,577 CNY hm-2 at a cutting time of 30 days after the flowering stage while the stubble height was 10 cm, and dependent on the forage yield of the main crop; in 2019, the maximum net income of FFRR was 27,326 CNY hm-2 at a cutting time of 10 days after the flowering stage while the stubble height was 10 cm, and dependent on the grain yield of the ratoon crop. Therefore, the optimal cultivation practice of the FFRR (cutting at 30 days after the flowering stage and with a stubble height of 10 cm) showed higher carbon and energy use effi-ciency, economic benefits of the FFRR were fluctuated with the price of forage of the main crop and rice grain of the ratoon crop.
作者机构：
[邹丹; Liu L.; 毛瑞清; 张明] Hengyang Academy of Agricultural Sciences, Hengyang, 421200, China;[唐启源; 郑华斌] College of Agronomy, Hunan Agricultural University, Changsha, 410128, China;[旷娜] Hunan Rice Research Institute, Changsha, 410128, China;[刘龙生] Agricultural Bureau of Youxian, Zhuzhou, 412300, China
