There is a need to comprehensively evaluate the rice quality of different rice varieties under different nitrogen treatments. Therefore, in this study, we used twenty-one hybrid indica rice varieties and twenty-three inbred japonica rice varieties with three nitrogen fertilizer levels to investigate differences in rice qualities. As compared with hybrid indica rice, inbred japonica rice had lower coefficient of variation values for grain shape, mild rice percentage, and head rice percentage, but relatively higher coefficient of variation values for chalkiness traits, appearance, and taste value of cooked rice. A principal component analysis and membership function method were used to comprehensively evaluate the qualities of rice. The overall eating quality value by sensory evaluation and head rice percentage explained 61.3% and 67.9% of the variations in comprehensive quality of hybrid indica rice and inbred japonica rice across different nitrogen levels, respectively. We also found that rice comprehensive quality was better under low nitrogen levels for hybrid indica rice, while for inbred japonica rice, properly increasing nitrogen application could improve the comprehensive quality.
The MADS-box protein is an important transcription factor in plants and plays an important role in regulating the plant abiotic stress response. In this study, a total of 94 MADS-box genes were predicted in the litchi genome, and these genes were widely distributed on all the chromosomes. The LcMADS-box gene family was divided into six subgroups (Mα, Mβ, Mγ, Mδ, MIKC, and UN) based on their phylogenetical relationships with Arabidopsis, and the closely linked subgroups exhibited more similarity in terms of motif distribution and intron/exon numbers. Transcriptome analysis indicated that LcMADS-box gene expression varied in different tissues, which can be divided into universal expression and specific expression. Furthermore, we further validated that LcMADS-box genes can exhibit different responses to various stresses using quantitative real-time PCR (qRT-PCR). Moreover, physicochemical properties, subcellular localization, collinearity, and cis-acting elements were also analyzed. The findings of this study provide valuable insights into the MADS-box gene family in litchi, specifically in relation to stress response. The identification of hormone-related and stress-responsive cis-acting elements in the MADS-box gene promoters suggests their involvement in stress signaling pathways. This study contributes to the understanding of stress tolerance mechanisms in litchi and highlights potential regulatory mechanisms underlying stress responses.
Abstract To explore the role of jasmonic acid in seed germination of rice under Cd stress, the growth indices of JJ818 and NJ9108 under the bud stage were measured for identifying study the molecular mechanism of variety difference in cadmium tolerance. The tolerant variety JJ818 and the sensitive variety NJ9108 were treated under 150 µmol·L − 1 Cd concentration, methyl jasmonate (MeJA), and Ibuprofen (IBU) alone or in combination. The germination rate, root length, bud length, soluble protein content, soluble sugar content, and sugar components, α-amylase activity, and its related gene expression were measured. The results showed that the root length of the two rice materials were significantly inhibited during germination under the Cd treatment, however, the germination rate and shoot length had little affected. MeJA decreased the germination rate, root length and shoot length, and the contents of soluble sugar and sugar components and α-amylase activity as well. However, IBU treatment showed the opposite trend. Cd treatment also decreased the expression of the αAmy and RL1 , and the accompanying changes of up-regulated the gene expression of JIOsPR10 , OsLOX1 , and OsLOX4 related to synthesizing jasmonic acid(JA). The results showed that JA negatively regulates the cadmium of rice and the genes related to the synthesis and response of JA were related to the variety difference in cadmium tolerance at the bud stage. Compared with the NJ9108, JJ818 was insensitive to jasmonic acid.
Salinity stress is an important environmental constraint limiting the productivity of many crops worldwide. In this report, experiments were conducted to investigate the effects of seed presoaking by bovine hemoglobin, an inducer of heme oxygenase-1 (HO-1), on salinity tolerance in rice (Oryza sativa) plants. The results showed that different concentrations of the hemoglobin (0.01, 0.05, 0.2, 1.0, and 5.0 g/L) differentially alleviated the inhibition of rice seed germination and thereafter seedling shoot growth caused by 100 mM NaCl stress, and the responses of 1.0 g/L hemoglobin was the most obvious. Further analyses showed that application of hemoglobin not only increased the HO-1 gene expression, but also differentially induced catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) activities or transcripts, thus decreasing the lipid peroxidation in germinating rice seeds subjected to salt stress. Compared with non-hemoglobin treatment, hemoglobin presoaking also increased the potassium (K) to sodium (Na) ratio both in the root and shoot parts after salinity stress. The effect is specific for HO-1 since the potent HO-1 inhibitor zinc protoporphyrin IX (ZnPPIX) blocked the positive actions of hemoglobin on seed germination and seedling shoot growth. Overall, these results suggested that hemoglobin performs an advantageous role in enhancement of salinity tolerance during rice seed germination.
Abstract Milling quality (MQ) and grain shape (GS) of rice ( Oryza sativa L.) are correlated traits and both determining farmers’ final profit. More than one population under multiple environments may provide valuable information for breeding selection on this MQ-GS correlations. However, suitable analytical methods for reciprocal introgression lines with linkage map for this kind of correlation remains unclear. In this study, our objectives were (1) to provide a set of reciprocal introgression lines (composed by two BC 2 RIL populations) suitable for mapping by linkage mapping using markers/bins with physical positions; (2) to test mapping effect by MQ-GS correlation dissection by different mapping methods; (3) to perform genetic and breeding simulation to pyramid favorite alleles of QTLs for representative MQ-GS traits. Finally, with four analysis methods and data collected under five environments, we identified about 28.4 loci in average for MQ-GS traits. It’s notable that 52.3% of these loci were commonly detected by different methods and eight loci were novel. There were also nine regions harboring loci for different MQ-GS traits which may be underlying the MQ-GS correlations. Background independent (BI) loci were also found for each MQ and GS trait. All these information may provide useful data for rice molecular breeding.
Wind power, photovoltaic and hydropower (referred to as scenery and water) complementary power generation system is an important innovative mode to improve the overall efficiency of clean energy utilization. With the vigorous development of clean energy, how to solve the problem of flexibility demand brought by the large-scale grid connection of new energy has become the core and difficult point in the research and development of multi-energy complementary system. In this paper, we firstly consider the uncertainty of scenery output and use regression analysis to predict the scenery output; secondly, we make use of the good regulation performance of hydropower units to smooth out the uncertainty of scenery output and propose a short-term scheduling model based on adaptive variational particle swarm optimization algorithm to efficiently and accurately define the output size of hydropower units. The development of short-term optimal dispatching strategy will help promote the healthy development of clean energy in China.
Abstract Chromosome segment substitution lines ( CSSL s) provide ideal materials for quantitative trait loci ( QTL s) mapping and genetic dissection of complex traits. In this study, we developed a set of CSSL population consisting of 175 lines, which were derived between the recipient ‘Guangluai 4’ and the donor ‘Nipponbare’. Based on 260 molecular markers, we firstly constructed a physical map of core 97 lines. Then, these 97 lines were further genotyped based on resequencing data, and a resequencing‐based physical map was constructed. Compared with the molecular marker‐based physical map, the resequencing‐based physical map of 97 lines contained 367 substituted segments with 252 newly discovered segments. The total size of the 367 substituted segments was 1,074 Mb, which was 2.81 times the size of rice genome. Using the 97 CSSL s as materials, we identified nine QTL s for heading date and three of them were firstly reported. All the QTL s had positive additive effects, ranging from 9.50 to 16.50 days. These CSSL s may greatly help forge a new resource for functional genomics studies and molecular breeding in rice.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)