Supervisor(s): Ministry of Agriculture Sponsor(s): Chinese Academy of Agricultural Sciences；Chinese Association of Agricultural Science Societies CN：11-1328/S
Scientia Agricultura Sinica, the 1st in Comprehensive Agricultural Science, is supervised by Ministry of Agriculture of PRC, and sponsored by Chinese Academy of Agricultural Sciences; Chinese Association of Agricultural Science Societies. Scientia Agricultura Sinica, launched in 1960, is a leading peer-reviewed and mufti-disciplinary journal and published semi-monthly in Chinese with English title, abstract, figures, tables and references. It aims to publish those papers that are influential and will significantly advance scientific understanding in agriculture fields worldwide. The scope covers Crop Genetics, Breeding, Germplasm Resources; Physiology, Biochemistry, Cultivation, Tillage Plant Protection; Soil & Fertilization, Agro-Ecology & Environment, Bio-energy; Animal Science, Veterinary Science, Agricultural Information Science; Food Science; Agricultural Economics and Management; Agricultural Sustainability.
The journal is included in JST, CA and CSCD.
Editor-in-Chief Wan Jianmin Associate Editor-in-Chief Zou Ruicang Tang HuaJun Wu Kongming Guo YuYuan Geng Xu Sun Tan Executive Editor Lu Wenru
[Objective] The purposes of this study are to fine map a grain length-associated QTL from wild rice using a chromosome segment substitution line (CSSL) and secondary population, explore new genes affecting grain length, and provide genetic materials and gene resources for rice breeding. [Method] Our laboratory had preliminary mapped a grain length-related QTL,
qGL12, using the CSSL population. On this basis, we chose one CSSL, CSSL141, which harbors
qGL12 substitution segment and has significant difference in grain length with receptor parent 9311, to backcross with 9311. The secondary segregation population was constructed for fine mapping of
qGL12. Detection of length of glume cells was performed by the scanning electron microscope. [Result] CSSL141 has four introgressive segments from wild rice and its grain length, grain width, and grain weight were significantly higher than those of 9311 under multiple conditions. By using CSSL141/9311 F
2 population,
qGL12 was localized to the interval between RM5479 and RM28621 on chromosome 12.
qGL12 affected grain length, grain width, and grain weight, and the phenotypic variation explained of grain length was 44.61%. Seven polymorphic molecular marker primers in the location interval were designed and F
3 plants which had heterozygous genotype in the target interval were investigated.
qGL12 was mapped to a 50-kb region between RM5479 and RM28586. Four polymorphic molecular marker primers were designed in this resion and individuals which harbor heterozygous genotype in this interval were selected for the next generation F
4. Eventually,
qGL12 was narrowed to a 15.69-kb region between DYB9.1 and RM28586 on chromosome 12. There are 3 genes in the interval. Two candidate genes,
Os12g39650 and
Os12g39660, encode a tubulin and a calcium-transporting ATPase, respectively, with variation in their coding regions. The results of electron microscope scanning of glume cells showed that the length and width of 9311’s glume cells were smaller than those of CSSL141, indicating that
qGL12 regulated grain shape of rice by controlling the size of glume cells. [Conclusion] The wild rice grain length-associated QTL,
qGL12, was fine mapped to a 15.69-kb region on chromosome 12.
qGL12 controlled grain length by regulating the size of glume cells. Two candidate genes,
Os12g39650 and
Os12g39660, were found and would be used for further research.
[Objective] The objective of this study was to locate and annotate the major histocompatibility complex (MHC) gene sequence of Bactrian camel in order to provide scientific basis for further study on Bactrian camel MHC gene. [Method] This study used comparative genomics method. The human MHC (HLA) gene coding sequence and bovine MHC (BoLA) gene coding sequence were extracted, compared with the Bactrian camel transcripts on the gene sequences through blastn, to identify the scaffolds with higher similarity. By analyzing the sequence of HLA and BoLA gene sequences on their positions on these scaffolds, multiple pieces of scaffolds were assembled to obtain the Pseudo chromosome of Bactrian camel MHC. Then, the human MHC (HLA) gene coding sequence and bovine MHC (BoLA) gene coding sequence were extracted and analyzed with the assembled scaffolds of Bactrian camels through the genomic collinearity analysis. The selected scaffolds could be judged whether or not it was accurate, based on the linear relationship between Pseudo chromosome established by lastz and HLA and BoLA genome sequences; then by analyzing the linear relationship between MHC genes in the two species, the MHC gene sequences were extracted from Bactrian camel genomes, and these sequences were genetically annotated; finally, according to the obtained Bactrian camel MHC gene, the phylogenetic tree was drawn to study the evolutionary relationship between their genes. [Result] By comparing the HLA and BoLA gene coding sequences with the Bactrian camel transcripts through blastn, three scaffolds with high similarity were identified, namely NW_011511766.1 (full-length 4.1 M), NW_011515227.1 (full-length 1.2 M) and NW_011514613.1 (15 K in total length), and assembled to obtain Bactrian camel MHC Pseudo chromosome; By using the lastz collinearity analysis, the HLA gene sequence and the BoLA gene sequence were identified and compared with the MHC gene of the Bactrian camel to obtain the colinear region. It was consistent with the assembled Pseudo chromosome, which proved that the selected scaffolds were accurate. It was found that Class-Ⅰ and Class-Ⅲ genes were distributed on NW_011515227.1, while Class-Ⅱ genes were distributed on NW_011511766.1 and NW_011514613.1. Further analysis revealed that Class-Ⅱ genes were mainly distributed in NW_011511766.1 3.5 to 4.1 M position; the sequences that existed in the collinear region were extracted and subjected to blat analysis, namely aligned with the coding sequence of the MHC gene on the Bactrian camel. The results reveal that a total of 24 genes highly similar to bovine BoLA gene were identified in Bactrian camel genome, including 1 of Class Ⅰ gene, 10 of Class Ⅱ gene and 13 of Class Ⅲ gene. The 24 MHC genes of Bactrian camels were annotated and phylogenetic trees were mapped. The results showed that the annotated Class-Ⅰ and Class-Ⅱ genes were in the same branch. [Conclusion] The method of locating and annotating the MHC gene sequence in Bactrian camel was established by comparative genomics. The MHC gene sequence of Bactrian camel was mapped to three scaffolds, 24 MHC genes were found and annotated, and the Pseudo chromosome of the MHC gene of the Bactrian camel was drawn, which laid the foundation for further study of Bactrian camel MHC gene.
[Objective] The objective of this study was to explore the effects of late frost stress on plant height and its components in winter wheat, and to clarify the characteristics of plant height reduction and its relationship with internode length, ear length, and grain yield, in order to provide a basis for establishing the evaluation index of late frost damage. [Method] By using two frost simulation means based on the Cold Climate Chamber and the Field Movable Climate Chamber, six pot experiments and three plot experiments were carried out with the developmental progresses [floret primordia differentiation (FPD), pistil and stamen primordia differentiation (PSPD), anther connective tissue formation (ACTF), tetrad formation (TF) and heading phase] of young ear and the subfreezing treatment temperatures (−1 °C, −3 °C, −5 °C, −7 °C, −9 °C, and −11 °C) as the gradients. The culm damage was investigated after each frosting treatment, and the plant height and its components, and grain yield were measured at maturity. Variance analysis, regression function fitting and test method for sudden change were used to study the rule of plant height reduction, the contribution of each component to plant height, and the regression relationship of plant height and grain yield. [Result] (1) At the stages of PSPD to late ACTF, the plant height generally showed a decreasing trend with the decrease of treatment temperature. When the treatment temperature was lower than −5 °C or so, a sudden change began, and there was certain difference between individual plants and cultivars. At the same treatment temperature, the greatest decline in plant height occurred at the late ACTF stage. (2) At the stages of PSPD, early ACTF, and late ACTF, the fourth internode length from the top (FIL), antepenultimate internode length (AIL), penultimate internode length (PIL), and ear length (EL) all showed shortening trends to different degrees under the frost stress. In these periods, the two key internodes contributing to plant height were FIL and AIL, AIL and PIL, and PIL and FIL, respectively, that showed a strongly significant correlation (
P < 0.001) with plant height. Correspondingly, the plant height significantly decreased. (3) The regression curves of plant height with kernel number per ear, 1 000-kernel weight, and yield per plant, were well fitted by the power function models. The reduction in yield per plant showed a trend from the rapid to the slow as plant height decreased. When the yield per plant was reduced to 1.5 g or less because of the further frost stress, it became relatively stable as the plant height continued to decrease, also, the kernel number per ear did not change significantly any more at that time. [Conclusion] Under the simulated late frost stress, a significantly shortening trend occurred only in the imminent or elongated internodes and young ear, but not in the end of elongation. When the shortening internodes were consistent with the internodes that mainly contributed to the plant height, the plant height significantly decreased. Using the shortening feature of the internodes, and the power function model of plant height with yield per plant, a new approach could be provided for the risk assessment of plant lodging in late growth and yield loss of winter wheat affected by late frost.
Fungal, bacterial and viral diseases are serious threats to maize production. In China, maize has been planted in wide areas with different agri-ecologic types and about 30 important diseases occurred annually. Because of shorter research history and limited transmission of knowledge in maize diseases, there are some confusions in using the old pathogen names of maize diseases in China, and it affects the communication about maize diseases between researches. In this paper, six scientific names of pathogens, which causing common smut, head smut, red leaf disease, northern corn leaf spot, eyespot and black bundle disease respectively, were collated based on taxonomic history of the pathogens and advantages on modern morphological taxonomy and molecular systematics. (1) The morphological and molecular characters of causal agent of common smut showed that the agent was not closely related to species of
Ustilago. The name
Mycosarcoma maydis, given by Brefeld in 1912, was resurrected as the valid name for maize common smut pathogen, and
Ustilago maydis, a widely used name, was the synonym now. (2) Based on host selection, sporocarp morphology, host disease characteristics and result in multiple gene analyses within
Sporisorium,
Sphacelotheca and other related genera,
Sporisorium reilianum, re-established by Langdon & Fullerton in 1978, was described as the correct name of pathogen causing maize head smut. The name,
Sphacelotheca reiliana, was as one of synonyms. Because of host specificity between maize and sorghum, the maize pathogen also named as
Sporisorium reilianum f. sp.
zeae. (3) The virus
Barley yellow dwarf virus (BYDV) is generally considered to be causal agent of maize red leaf disease. Recently, some virus strains infected maize were sequenced, and the results show clearly that
Wheat yellow dwarf virus-GPV and
Maize yellow dwarf virus-RMV all belong to
Polerovirus genus, are pathogens causing the disease in China. (4) In spite of similar in morphology, but it is proved that genus
Kabatiella is completely different from the genus
Aureobasidium by multigene phylogenetic analyses. The correct name of pathogen causing maize northern corn leaf spot is
Kabatiella zeae, and
Aureobasidium zeae is its synonym. (5)
Helmintosporium-like fungi have undergone several changes in genera. By detailed analysis on morphology, the DNA sequence data, mode of life and novel metabolite production show that
Bipolaris zeicola, causing eyespot on maize, is a valid and conserved anamorph name. The name of
Bipolaris was protected over
Cochliobolus and approved by the Nomenclature Committee for Fungi. (6) The name
Cephalosporium acremonium was confusingly used to different fungi long-time and it has lost the strict concept of criterion species.
Acremonium, including more than 150 species, is also highly polyphyletic taxon with several teleomorph genera. The molecular biological characters showed the heterogeneity of the genus
Acremonium. By combining the molecular characteristics with morphology, old
Acremonium species were reclassified into some genera, and the name
Sarocladium strictum was given to the pathogen of maize black bundle disease with the synonyms
Cephalosporium acremonium and
Acremonium strictum.
[Objective] Under the irrigation mode controlled by cumulative radiation, the objective of this paper was to study on the effects of different irrigation amounts on tomato growth, water and fertilizer utilization in tomato flowering and fruit-set stage, so as to provide the scientific basis for efficient tomato production in Chinese solar greenhouses. [Method] Under the condition of soil ridge substrate embedded cultivation, the tomato for test was the hybrid cultivar “Fengshou” and the drip irrigation of the nutrient solution was adopted. The irrigation modes included conventional irrigation with a regular time interval (hereinafter referred to as CK) and irrigation controlled by cumulative radiation, which was divided into low irrigation (T1), middle irrigation (T2) and high irrigation (T3). The differences in growth, development, and water and fertilizer utilization of tomato at the flowering and fruit-set stages influenced by the irrigation mode and quantity were explored. [Result] Compared with CK, the irrigation amounts of T1, T2 and T3 were reduced by 39.3%, 30.3% and 14.0%, respectively. The greater irrigation amount resulted in higher substrate moisture content, which was ranked in a descending order as follow: CK > T3 > T2 > T1. The irrigation controlled by cumulative radiation was better for tomato vegetative and reproductive growth, and it significantly improved the tomato biomass. Compared with the CK treatment, the tomato biomasses of T1, T2 and T3 were increased by 57.1%, 75.3% and 32.7%, respectively. Among them, the tomato biomass of treatment T2 was 102.9 g·plant
−1, which was also significantly higher than those of T1 and T3. Controlled by the cumulative radiation, the irrigation amount in the sunny day was more than that in the cloudy day, and the irrigation amount at noon time was more than those in the morning and afternoon, more consistent with the plant’s demand for water and fertilizer. Besides, it saved the water and fertilizer and avoided the waste of water and fertilizer. Compared with CK, the drainage rates of T3 on sunny and cloudy days were reduced by 62.5% and 72.6%, respectively. The suitable irrigation amount controlled by cumulative radiation also significantly improved the tomato yield and irrigation water utilization efficiency. Compared with CK, the tomato yield of T2 was improved by 14.2%, reaching up to 61.3 t·hm
−2, and the irrigation water utilization efficiency was improved by 34.1%. The insufficient irrigation inhibited the production of plants. [Conclusion] The irrigation controlled by cumulative radiation could promote the growth and effectively save the water and fertilizer. Among them, the irrigation amount of T2 was 533.0 m
3·hm
−2, which could be used as the reference quantity of nutrient solution for tomato during the flowering and fruit-set stages in Chinese solar greenhouses.
