摘要：
Graphical Abstract and Lay Summary The SPAD value is directly proportional to the nitrogen nutrition of crops. By analyzing the SPAD value, the growth status of plants can be understood, agricultural production management measures can be adjusted in a timely manner, and crop growth and development can be optimized. In this study, a widely used feature extraction method was introduced in finance and stock markets, namely MF‐DFA, to extract multifractal features of cotton canopy spectra, and introduced vegetation index for feature fusion. A hyperspectral feature fusion SPAD value inversion model and a recognition model with different fertilization rates was proposed, achieving excellent model performance. This provides more reference for crop parameter inversion and recognition research. Abstract Hyperspectral remote sensing technology is becoming increasingly popular in various fields due to its ability to provide detailed information about crop growth and nutritional status. The use of hyperspectral technology to predict SPAD (Soil and Plant Analyzer Development) values during cotton growth and adopt precise fertilization management measures is crucial for achieving high yield and fertilizer efficiency. To detect the nitrogen nutrition in cotton canopy leaves quickly, a non‐destructive nitrogen nutrition retrieval model was proposed based on the spectral fusion features of the cotton canopy. The hyperspectral vegetation index and multifractal features were fused to predict the SPAD value and identify the amount of fertilizer applied at different levels. The random decision forest algorithm was used as the model predictor and classifier. A method was introduced which was widely used in the fields of finance and stocks (MF‐DFA) into the field of agriculture to extract fractal features of cotton spectral reflectance. Comparing the fusion feature with multi‐fractal feature and vegetation index, the results showed that the fusion feature parameters had higher accuracy and better stability than using a single feature or feature combination. The R2 was as high as 0.8363, and the RMSE was 1.8767%. Our intelligent model provides a new idea for detecting nitrogen nutrition in cotton canopy leaves rapidly.
摘要：
Peanut is an economically-important oilseed crop and needs a large amount of calcium for its normal growth and development. Calcium deficiency usually leads to embryo abortion and subsequent abnormal pod development. Different tolerance to calcium deficiency has been observed between different cultivars, especially between large and small-seed cultivars. In order to figure out different molecular mechanisms in defensive responses between two cultivars, we treated a sensitive (large-seed) and a tolerant (small-seed) cultivar with different calcium levels. The transcriptome analysis identified a total of 58 and 61 differentially expressed genes (DEGs) within small-seed and large-seed peanut groups under different calcium treatments, and these DEGs were entirely covered by gene modules obtained via weighted gene co-expression network analysis (WGCNA). KEGG enrichment analysis showed that the blue-module genes in the large-seed cultivar were mainly enriched in plant-pathogen attack, phenolic metabolism and MAPK signaling pathway, while the green-module genes in the small-seed cultivar were mainly enriched in lipid metabolism including glycerolipid and glycerophospholipid metabolisms. By integrating DEGs with WGCNA, a total of eight hub-DEGs were finally identified, suggesting that the large-seed cultivar concentrated more on plant defensive responses and antioxidant activities under calcium deficiency, while the small-seed cultivar mainly focused on maintaining membrane features to enable normal photosynthesis and signal transduction. The identified hub genes might give a clue for future gene validation and molecular breeding to improve peanut survivability under calcium deficiency.
摘要：
Excessive nitrogen and insufficient calcium could significantly impact peanut yields. This study investigated the effects of nitrogen and calcium fertilizers on nutrient absorption, utilization, and yield; experiments were conducted using the peanut cultivar from Xianghua 2008 in a split-plot arrangement with two calcium fertilizer levels (Ca-0: 0 and Ca-1: 568 kg CaO ha(-1)) in the main plots and six nitrogen fertilizer gradients (N-0: 0, N-45.0: 45.0, N-90.0: 90.0, N-112.5: 112.5, N-135.0: 135.0, and N-157.5: 157.5 kg N ha(-1)) in subplots between 2015 and 2016 in Changsha, China. We examined the impact of different rates of calcium and nitrogen fertilizers on the net photosynthetic rate (Pn), agronomic traits, dry matter quality, yield and yield composition, nutrient accumulation, and distribution. The combined application of calcium and nitrogen fertilizers significantly affected the yield and yield components, Pn, main stem height, dry matter, and nutrient accumulation. Under the same calcium level, nitrogen application significantly increased the main stem height and Pn and promoted the accumulation of dry matter and nutrients in the plant, particularly in the kernel. Under the same nitrogen treatment, calcium significantly increased Pn and promoted the accumulation of dry matter, calcium, and magnesium. The pod yield increased gradually with an increasing nitrogen application rate (0-112.5 kg ha(-1)) and peaked at N-112.5, increasing by 52.3-138.0% compared with N-0. However, excessive nitrogen application (N > 112.5 kg ha(-1)) decreased the pod yield. Under different nitrogen fertilizer levels, calcium application increased pod yields by 11.5-29.6% by promoting Pn, nutrient uptake, accumulation in the individual plant, and nutrient accumulation in the kernel. Therefore, this study suggested that adjusting the calcium (568 kg ha(-1)) and nitrogen (112.5 kg ha(-1)) fertilizer rates significantly improved peanut growth and productivity by enhancing photosynthetic efficiency and nutrient accumulation in calcium-deficient acidic red soil.
摘要：
The application of nitrogen fertilizer is crucial to the growth and biological nitrogen fixation of peanut, especially in the seedling stage where nodules have not yet formed. However, it is still uncertain how much initial nitrogen fertilizer should be applied to promote peanut root growth, nodule formation, and biological nitrogen fixation (BNF). There, a 2-year pot experiment was conducted using Huayu 22 (HY22, large-grain cultivar) and Huayu 39 (HY39, small-grain cultivar) as experimental materials to research the effects of different initial nitrogen fertilizer application rates on peanut root growth (root weight, root length, root mean diameter, root activity) and biological nitrogen fixation capacity (nodule number, nodule weight, biological nitrogen fixation, and nitrogen fixation potential per plant). N-0, as control, four initial nitrogen fertilizer application rates were established: 15 kg<middle dot>hm(-2) (N-15), 30 kg<middle dot>hm(-2) (N-30), 45 kg<middle dot>hm(-2) (N-45), and 60 kg<middle dot>hm(-2) (N-60). The present results showed that the nodule number, nodule dry weight, nitrogenase activity, and biological nitrogen fixation of the HY22 cultivar under the N-15 treatment were higher compared to those under other treatments over the two growing seasons. In addition, the cultivar of HY39 treated with the N-15 treatment also increased the nitrogen fixation potential per plant and BNF relative to other treatments. Although the application of 60 kg<middle dot>hm(-2) nitrogen increased the root surface area and root volume, it decreased the nitrogenase activity, nodule dry weight, and nitrogen fixation potential per plant of HY22 and HY39 varieties in both growing seasons. Above all, an initial nitrogen application of 15 kg<middle dot>hm(-2) may be the optimal treatment for promoting peanut nodule formation and biological nitrogen fixation.
通讯机构：
[Li, L; Luo, ZA ] H;Hunan Agr Univ, Coll Agr, Changsha, Hunan, Peoples R China.;Hunan Agr Univ, Arid Land Crop Res Inst, Changsha, Hunan, Peoples R China.;Hunan Peanut Engn & Technol Res Ctr, Changsha, Hunan, Peoples R China.
关键词：
antioxidant enzymes;calcium deficiency;calcium uptake and distribution;peanut;peanut yield
摘要：
Peanut yield in southern China is usually limited by calcium deficiency in soil. Most previous studies have found that small-seed varieties showed higher tolerance than large-seed varieties (e.g. Virginia type) under calcium deficiency, however, our preliminary research found that sensitive varieties also existed in small-seed counterparts. Few studies have been conducted to characterize low-calcium tolerance among small-seed germplasms with genetic diversity, and the differences in physiological characteristics between sensitive and tolerant varieties has not been reported yet. Thus, in order to better understand such differences, the current study firstly collected and characterized a diversity germplasm panel consisting of 50 small-seed peanut genotypes via a 2-year field trial, followed by the physiological characterization in sensitive (HN032) and tolerant (HN035) peanut genotypes under calcium deficiency. As a result, the adverse effects brought by calcium deficiency on calcium uptake and distribution in HN032 was much larger than HN035. In details, calcium uptake in the aboveground part (leaves and stems) was reduced by 16.17% and 33.66%, while in the underground part (roots and pods), it was reduced by 13.69% and 68.09% under calcium deficiency for HN035 and HN032, respectively; The calcium distribution rate in the pods of HN035 was 2.74 times higher than HN032. The utilization efficiency of calcium in the pods of HN035 was 1.68 and 1.37 times than that of HN032 under calcium deficiency and sufficiency, respectively. In addition, under calcium deficiency conditions, the activities of antioxidant enzymes SOD, POD, and CAT, as well as the MDA content, were significantly increased in the leaves of HN032, peanut yield was significantly reduced by 22.75%. However, there were no significant changes in the activities of antioxidant enzymes, MDA content, and peanut yield in HN035. Therefore, higher calcium absorption and utilization efficiency may be the key factors maintaining peanut yield in calcium-deficient conditions for tolerant genotypes. This study lays a solid foundation for selecting low-calcium tolerant varieties in future peanut breeding.
作者机构：
[Chen, Xiaojun; Li, Li; Tang, Qing; Deng, Canhui; Dai, Zhigang; Zhang, Xiaoyu; Cheng, Chaohua; Chen, Jiquan; Su, Jianguang; Xu, Ying; Yang, Zemao] Chinese Acad Agr Sci, Inst Bast Fiber Crops, Changsha 410205, Peoples R China.;[Yu, Shuhao] Oklahoma State Univ, Dept Hort & Landscape Architecture, Stillwater, OK 74078 USA.;[Sun, Jian] Nantong Univ, Sch Life Sci, Nantong 226000, Peoples R China.;[Chen, Xiaojun] Hunan Agr Univ, Coll Agron, Changsha 410128, Peoples R China.
通讯机构：
[Xiaoyu Zhang; Jianguang Su] I;Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha 410205, China<&wdkj&>Authors to whom correspondence should be addressed.
关键词：
Cannabis sativa L.;gene editing;CRISPR/Cas system
摘要：
Cannabis (Cannabis sativa L.) is a dioecious plant cultivated worldwide for thousands of years. Besides the narcotic and therapeutic effects, Cannabis can be used as raw materials in multiple fields, including bioenergy, textiles, food, and ecological restoration. It is also an efficient bioremediation agent for contaminated soil, as well as greenhouse gas absorption. With the expansion of the market, there has been an increased demand to develop Cannabis cultivars with enhanced traits. As a major science breakthrough, the advent of the CRISPR/Cas system will revolutionize the basic and applied research in Cannabis. This article provides an overview of the recent advances in the optimization of a transformation system and in the gene editing of Cannabis. To achieve the full potential of this environmentally friendly and sustainable crop, we highlight future directions of genetic modification as well as several bottlenecks to overcome.
作者机构：
[李林] College of Agronomy, Hunan Agricultural University, Changsha, 410128, China;[李新国; 徐杰; 南镇武; 郭峰; 孟维伟] Key Laboratory of Crop Genetic Improvement and Ecological Physiology of Shandong Province, Shandong Academy of Agricultural Sciences, Jinan, 250100, China;College of Life Science, Shandong Normal University, Jinan, 250000, China;[林松明; 万书波] College of Agronomy, Hunan Agricultural University, Changsha, 410128, China, Key Laboratory of Crop Genetic Improvement and Ecological Physiology of Shandong Province, Shandong Academy of Agricultural Sciences, Jinan, 250100, China;[张正] Key Laboratory of Crop Genetic Improvement and Ecological Physiology of Shandong Province, Shandong Academy of Agricultural Sciences, Jinan, 250100, China, College of Life Science, Shandong Normal University, Jinan, 250000, China
