摘要：
Whether the stems and leaves of leaf-vegetable sweet potatoes can be listed ahead of schedule is related to the improvement in economic benefits for farmers, and the key to all of this is to implement the safe overwintering of potato seedlings under the premise of saving production costs. Only in this way can we truly seize the "market opportunity" and achieve the goals of cost saving and increasing economic benefit. In this study, the main leaf-vegetable sweet potato variety Fucai 18 was used as the material, and the L9(3(4)) orthogonal experiment was carried out in a simple solar greenhouse environment for two consecutive years from 2021 to 2022 and from 2022 to 2023, respectively. The effects of nine different combinations of factors on the above-ground and underground agronomic traits of overwintering sweet potato seedlings were studied under the conditions of four factors and three levels: planting density (a); different cutting seedlings (b); rooting agent concentration (c); and transplanting time (d). The methods of principal component analysis, membership function method, cluster analysis, grey correlation degree and stepwise regression analysis were used to evaluate the growth of overwintering seedlings, and try to screen out the key indicators that can be used to identify and evaluate the growth of overwintering sweet potato seedlings. Through range analysis, identify the optimal combination of four factors and three levels, and explore the main factors that have a significant impact on the key indicators for evaluating the growth of overwintering potato seedlings. The results indicate the following: (1) The use of simple sunlight greenhouse in Changsha area can achieve the safe overwintering of vegetable sweet potato seedlings. (2) Stem thickness, root length, and root diameter can be used as three key indicators for identifying and evaluating the growth potential of vegetable sweet potato overwintering seedlings. (3) Under four factors and three levels, the best combination was A3B3C1D1 (planting density of 250,000 plants/ha, stem tip core-plucking seedlings, rooting agent concentration of 50 mg/L, the first batch of transplanting time). (4) The transplanting time (D) is the main factor for the two key evaluation indicators of stem diameter and root diameter, while there is no significant difference in the three other factors. (5) Different cutting seedlings (B) are the main influencing factors for the key evaluation index of root length, while the other three factors have the following impact on root length: transplanting time (D) > rooting agent concentration (C) > planting density (A). The results of this study not only contribute to the construction of a safe overwintering cultivation technology system for vegetable sweet potato seedlings, but also provide a certain theoretical basis for the breeding of new cold-leaf-vegetable sweet potato varieties in the future.
摘要：
<jats:p>Alkali stress is a significant challenge across the globe which is posing serious threat to crop production and food security. This study was carried out to study the effect of different levels of alkali stress on growth and physiological traits of <jats:italic>Leymus chinensis</jats:italic>. The study was comprised of different levels of alkali stress; control (CK; 0 mmol&middot;L<jats:sup>-1</jats:sup>), 25 and 50&nbsp;mmol&middot;L<jats:sup>-1</jats:sup>. The results showed that imposition of 50 mmol&middot;L<jats:sup>-1</jats:sup> alkali stress substantially reduced the photosynthetic capacity, relative water contents and accumulation of carbon (C), nitrogen (N) and phosphorus (P) in plant parts. Further, 50 mmol&middot;L<jats:sup>-1</jats:sup> alkali stress also reduced the above and below ground biomass, and severely inhibited the root growth. Moreover, increase in concentration of alkali stress inhibited clone components, tillering, tillering bud, and internode bud of <jats:italic>Leymus chinensis</jats:italic>. In conclusion the increasing concentration of alkali stress can reduce the growth and biomass production and nutrient accumulation of <jats:italic>Leymus chinensis</jats:italic>.</jats:p>
通讯机构：
[Peng, L ] H;Hunan Agr Univ, Coll Environm & Ecol, Changsha 410128, Peoples R China.
关键词：
Meteorological factors;Model;Rice;Soil cd;pH
摘要：
During the rice growth cycle, the average available cadmium concentration (C(A-Cd)) in the soil determines the Cd content in rice plant. Given defined soil properties and rice varieties, the meteorological factors play a crucial role in soil's available cadmium concentration (C(Cd)) during the rice growth cycle. Thus, it is significant to investigate the influence of meteorological factors in C(Cd) during the rice growth cycle and develop a predictive model for C(A-Cd). The rice was cultivated under seven different sowing dates in Cd and As-contaminated soil in Hunan Province. Studied the impact of meteorological factors on paddy soil. The results showed that accumulated temperature (AT) and total precipitation (TP) were key factors affecting the soil C(Cd). The correlation coefficients between AT and TP with soil C(A-Cd) were 0.98 and -0.94 (p<0.01), respectively. However, there was no significant correlation with C(As). AT mainly influenced the C(Cd) during the grouting and maturity stages. A straightforward empirical prediction model was developed, capable of accurately forecasting C(A-Cd) during the rice growth cycle by considering meteorological factors and the initial soil C(Cd). This study supported a novel foundation for the precise prediction of Cd content in rice.
关键词：
Low nitrogen;Photosynthetic -nitrogen use efficiency;Brassica napus L
摘要：
The photosynthetic -nitrogen use efficiency (PNUE) of Brassica napus L. is reported to increase under low nitrogen (N) condition. However, the underlying physiological mechanisms are unclear. In this study, the physiological mechanisms underlying increase in the photosynthetic -nitrogen use efficiency of Brassica napus L. under lownitrogen condition were investigated by assessing the changes in plant architecture, light reception, nitrogen allocation, and leaf tissue structure. The plants exhibited dwarf, upright, and compact phenotype under lownitrogen condition. Although the total photons received by plants decreased, the average photosynthetic photon flux density remained unchanged. The nitrogen photon reception efficiency (NPRE, calculated as total photons/N accumulation in leaves) was significantly increased by 76.61%-100.63%. The proportion of nitrogen allocated for photosynthesis was increased by 22.06%-38.86%. Moreover, although the leaf thickness remained unchanged, the epidermal thickness increased, and the spongy tissues became thinner. The density of mesophyll cells and chloroplasts significantly increased. Low -nitrogen condition significantly decreased the resistance to CO2 transport and significantly increased stomatal conductance (gs), intercellular carbon dioxide concentration (Ci), mesophyll conductance (gm), and CO2 concentration in chloroplasts (Cc). Correlation analysis revealed that light reception, nitrogen allocation in the leaves, and leaf tissue structure were significantly correlated with PNUE. Random forest analysis revealed that nitrogen photon reception efficiency and storage nitrogen were the primary factors positively and negatively impacting photosynthetic -nitrogen use efficiency, respectively. This study enhanced the understanding of the physiological mechanism of increased PNUE of B. napus under lownitrogen condition.
摘要：
Marginal lands, such as those with saline soils, have potential as alternative resources for cultivating dedicated biomass crops used in the production of renewable energy and chemicals. Optimum utilization of marginal lands can not only alleviate the competition for arable land use with primary food crops, but also contribute to bioenergy products and soil improvement. Miscanthus sacchariflorus and M. lutarioriparius are prominent perennial plants suitable for sustainable bioenergy production in saline soils. However, their responses to salt stress remain largely unexplored. In this study, we utilized 318 genotypes of M. sacchariflorus and M. lutarioriparius to assess their salt tolerance levels under 150 mM NaCl using 14 traits, and subsequently established a mini-core elite collection for salt tolerance. Our results revealed substantial variation in salt tolerance among the evaluated genotypes. Salt-tolerant genotypes exhibited significantly lower Na+ content, and K+ content was positively correlated with Na+ content. Interestingly, a few genotypes with higher Na+ levels in shoots showed improved shoot growth characteristics. This observation suggests that M. sacchariflorus and M. lutarioriparius adapt to salt stress by regulating ion homeostasis, primarily through enhanced K+ uptake, shoot Na+ exclusion, and Na+ sequestration in shoot vacuoles. To evaluate salt tolerance comprehensively, we developed an assessment value (D value) based on the membership function values of the 14 traits. We identified three highly salt-tolerant, 50 salt-tolerant, 127 moderately salt-tolerant, 117 salt-sensitive, and 21 highly salt-sensitive genotypes at the seedling stage by employing the D value. A mathematical evaluation model for salt tolerance was established for M. sacchariflorus and M. lutarioriparius at the seedling stage. Notably, the mini-core collection containing 64 genotypes developed using the Core Hunter algorithm effectively represented the overall variability of the entire collection. This mini-core collection serves as a valuable gene pool for future in-depth investigations of salt tolerance mechanisms in Miscanthus.
作者机构：
[Chen, Yinke; Peng, Yan; Teng, Zhenning; Duan, Meijuan; Ye, Nenghui; Qin, Zhonge; Liu, Bohan; Yu, Huihui; Ye, NH; Meng, Shuan; Lv, Jiahan; Duan, MJ] Hunan Agr Univ, Coll Agron, Hunan Prov Key Lab Rice Stress Biol, Changsha 410128, Peoples R China.;[Teng, Zhenning; Zhang, Jianhua; Yu, Huihui] Chinese Univ Hong Kong, Sch Life Sci, Hong Kong 999077, Peoples R China.;[Teng, Zhenning; Zhang, Jianhua; Yu, Huihui] Chinese Univ Hong Kong, State Key Lab Agrobiotechnol, Hong Kong 999077, Peoples R China.;[He, YC; He, Yuchi] Hubei Univ, Sch Life Sci, State Key Lab Biocatalysis & Enzyme Engn, Wuhan 430000, Peoples R China.;[Zhang, Jianhua; Ye, Nenghui; Ye, NH] Hong Kong Baptist Univ, Dept Biol, Hong Kong 999077, Peoples R China.
通讯机构：
[He, YC ; Zhang, JH; Ye, NH ; Duan, MJ] H;[Zhang, JH ] C;Hunan Agr Univ, Coll Agron, Hunan Prov Key Lab Rice Stress Biol, Changsha 410128, Peoples R China.;Chinese Univ Hong Kong, Sch Life Sci, Hong Kong 999077, Peoples R China.;Chinese Univ Hong Kong, State Key Lab Agrobiotechnol, Hong Kong 999077, Peoples R China.
摘要：
Low-temperature germination (LTG) is an important agronomic trait for direct-seeding cultivation of rice (Oryza sativa). Both OsMYB30 and OsTPP1 regulate the cold stress response in rice, but the function of OsMYB30 and OsTPP1 in regulating LTG and the underlying molecular mechanism remains unknown. Employing transcriptomics and functional studies revealed a sugar signaling pathway that regulates seed germination in response to low temperature (LT). Expression of OsMYB30 and OsTPP1 was induced by LT during seed germination, and overexpressing either OsMYB30 or OsTPP1 delayed seed germination and increased sensitivity to LT during seed germination. Transcriptomics and qPCR revealed that expression of OsTPP1 was upregulated in OsMYB30-overexpressing lines but downregulated in OsMYB30-knockout lines. In vitro and in vivo experiments revealed that OsMYB30 bound to the promoter of OsTPP1 and regulated the abundance of OsTPP1 transcripts. Overaccumulation of trehalose (Tre) was found in both OsMYB30- and OsTPP1-overexpressing lines, resulting in inhibition of alpha-amylase 1a (OsAMY1a) gene during seed germination. Both LT and exogenous Tre treatments suppressed the expression of OsAMY1a, and the osamy1a mutant was not sensitive to exogenous Tre during seed germination. Overall, we concluded that OsMYB30 expression was induced by LT to activate the expression of OsTPP1 and increase Tre content, which thus inhibited alpha-amylase activity and seed germination. This study identified a phytohormone-independent pathway that integrates environmental cues with internal factors to control seed germination. Low temperature increases the abundance of a transcription factor, which activates the biosynthesis of trehalose and consequently inhibits seed germination by impeding alpha-amylase activity in rice.
关键词：
Zhu Liangyou 819;leaf area index;dry matter;nitrogen use efficiency;yield
摘要：
Optimizing nitrogen fertilizer management can effectively improve soil ecology, promote agricultural production, and increase the income of farmers and workers. Nitrogen fertilizer is an important factor in the growth and development of rice, and it is important to find out the optimal amount and frequency of fertilizer application for the super-hybrid early rice 'Zhu LiangYou 819' in Hunan Province, to give full play to its high quality and high yield characteristics. Various N fertilizer application frequencies (P1, basal-tiller fertilizer = 5:5; P2, basal-tiller-spike fertilizer = 4:3:3; P3, basal-tiller-spike-grain fertilizer = 4:3:2:1) and N application amounts (N1, 90 kg ha(-)(1); N2, 150 kg ha(-)(1); N3, 210 kg ha(-)(1)) were applied to the hybrid rice ZLY819. The results show that, under the same frequency of N application, ZLY819 had the highest yield, agronomic efficiency, and physiological utilization rate of N fertilizer with the N2 treatment, averaging 7.53 t ha(-)(1), 18.10 kg kg(-)(1), and 34.34%, respectively, with the yield under N2 being 19.38% higher than that under N1. For the same amount of N application, the yield, agronomic efficiency, partial factor productivity of N (PFPN), N contribution to seed, and N use efficiency (NUE) increased with an increase in the frequency of N application, mainly in the order of P3 > P2 > P1, whereby the yield of P3 was 10.11% higher than that of P1. According to the regression equation, the yield is higher when the amount of nitrogen application is 202.15 kg ha(-)(1) and the fertilization frequency is four times. Appropriate N fertilizer management (P3N2) improved the rice growth characteristics, dry matter accumulation, crop growth rate, dry matter transport rate, dry matter contribution rate, and NUE, thus promoting an increase in the rice yield and efficient use of nitrogen.
摘要：
The scarcity of arable land and the problem of food security urgently called for a strategy of Remediation-byProduction (RBP). Biochar is a promising method for addressing Cd-contaminated soils, but the time required for remediation and the variability of long-term performance have a direct impact on the realization of the RBP strategy. We have developed a novel approach for remediating cadmium-contaminated flooded soil by utilizing lignin biochar (LBC) in combination with safe rice cultivation. The addition of 1 % LBC achieves efficient Cd passivation (CP: 90.89 %) before rice Cd uptake peaks. Meanwhile, LBC can increase soil organic matter and alter microbial community structure, decreasing the relative abundance of soil pathogenic bacteria from 5.12 % to 4.03 % while raising nutritional bacteria from 15.18 % to 28.82 %. Furthermore, LBC successfully reduced the accumulation of Cd in rice grains by 31.3 % similar to 54.6 %, making rice dwarf, sturdy, and greener, and lowering the health risk coefficients of Cd across various age groups by Monte Carlo simulations. This study elucidated the critical role of humic substances of LBC in remediation time and performance and laid a solid theoretical foundation for promoting the application of biochar in soil contamination remediation and simultaneously realizing the safe production of crops.
摘要：
With the sharp increase of the global population, adequate food supply is a great challenge. Grain size is an essential determinant of rice yield and quality. It is a typical quantitative trait controlled by multiple genes. In this paper, we summarized the quantitative trait loci (QTL) that have been molecularly characterized and provided a comprehensive summary of the regulation mechanism and genetic pathways of rice grain size. These pathways include the ubiquitin-proteasome system, G-protein, mitogen-activated protein kinase, phytohormone, transcriptional factors, abiotic stress. In addition, we discuss the possible application of advanced molecular biology methods and reasonable breeding strategies, and prospective on the development of high-yielding and high-quality rice varieties using molecular biology techniques.
摘要：
Regenerated rice, characterized by single planting and double harvesting, saves labor and costs, significantly contributing to global food security. Hyperspectral imaging technology, which integrates image and spectral data, provides comprehensive, non-destructive, and pollution-free vegetation canopy analysis, making it highly effective for crop nutrient diagnosis. In this study, we selected two varieties of regenerated rice for field trials. Hyperspectral images were captured during key growth stages (flush, grouting, and ripening) of both the first and regenerated seasons. Utilizing a two-dimensional convolutional neural network (2D-CNN) as a deep feature extractor and a fully connected layer for nitrogen content prediction, we developed a robust model suitable for estimating nitrogen content in regenerated rice. The experimental results demonstrate that our method achieves a mean squared error (MSE) of 0.0008, significantly outperforming the back-propagation (BP) network and multiple linear regression by reducing the MSE by 0.0151 and 0.0247, respectively. It also surpasses the one-dimensional convolutional neural network (1D-CNN) by 0.003. This approach ensures accurate nitrogen content prediction throughout the growth cycle of regenerated rice, aiding in yield and economic benefit enhancement.
