To effectively cope with the shock of COVID-19 and its subsequent impact, and to promote stable and healthy development of rape industry, this paper systematically analyzed the impact of COVID-19 on China's rape industry. It includes perspectives of farmer's life, rape production and rapeseed processing enterprises, based on micro survey data provided by the National Rapeseed Industrial Technology System. The results showed that in terms of farmers' life, only 0.98% of the respondents were in a shortage of edible vegetable oil and 76.06% of them reflected no impact or a little impact on total household income. However, rural tourism decreased by 10.24 percentage points, and honey collecting behavior of bee farmers decreased by 4.6 points. On field production, 85.47% of the respondents reported "no change" and "small reduction" in field management workload, 90.38% reflected "no impact" and "a littlel impact" on rapeseed production employment, 79.06% considered "overall stability" in the price of agricultural materials, and 98.48% believed that it had a little impact on final output. However, the pest reporting rate increased by 4.99 points than last season. On rapeseed processing, it varied from region to region on the rapeseed processing enterprises' resumption rate, starting-up rate, specific difficulties faced by enterprises and government policies. Based on these results, future strategies should be taken to ensure improving development of rape industry. The strategies should include perfect construction of China's oil reserve system, more attention to diversification of imports, more innovation and technology promotion, optimization on marketing system and construction of information platform, and a“package”subsidy plan for the industry.
The genetic pattern of pod traits were analysed using the major gene plus polygene model in five combinations of F2 families of a nested crossing population in peanut to dissect the genetic variation in nested crossing population. Results revealed rich variations in the five pod traits in the nested combination. The ranges of pod length, pod width, and hundred-pod weight were（14.30-22.09）mm -（38.36-45.12）mm,（7.06-10.47）mm -（17.13-22.74）mm, and（62.41-94.38）g -（266.75-364.00）g, respectively. There was a strong positive correlation between pod length and pod width, pod surface area, pod surface perimeter and hundred-pod weight, but little correlation with ratio of pod length to pod width; pod width was positively correlated with pod surface area, pod surface perimeter and hundred-pod weight, but negatively correlated with pod length to width ratio. The genetic models of different pod traits in different combinations were different, and the best genetic models were two major gene of additive - dominant model and two major gene of additive - dominant - epistatic model. The heritability of major genes was 22.79% - 91.62%, and the genetic effects of the major genes in different families differed to each other, which implied the effects of multiple alleles or non-alleles as well as the genetic background on the pod traits. The results provide material and genetic basis for the further QTL mapping of pod traits and peanut breeding of specific pod shapes.
Fat content is an important economic trait of peanut seed (Arachis hypogaea L.). The purpose of this study is to analyze the direct and maternal effects of fat content inheritance in peanut, so as to provide the strategy for the design of breeding program and developing related molecular markers in high fat content peanut breeding.Five peanut varieties of different plant types with different fat content, including Yuhua 9326, Yongcheng Xiaomake, Weihua 6, Zhanyou 62 and Quanhua 6, were selected as the parents for complete diallel cross. The fat content of seeds from the parents, F1 and F2 of 20 combinations were analyzed by Soxhlet residue method. The direct effect of embryo gene, maternal effect and their heritability were estimated using general genetic model. The results showed that when one of the parents had higher fat content and the other parent had more than medium fat content, the fat content of F1 would be higher. When the fat content of both parents was medium, or the fat content of one of the parents was lower, then the fat content of offspring was lower. The variance of direct additive effect was the largest, followed by maternal additive effect in the variation analysis. The variance of maternal dominant effect was small while no cytoplasmic effect was detected. Meanwhile, the heritability of seed direct effect was greater than that of maternal effect. The direct additive effect of parents with high fat content was positive, while that of parents with low fat content was negative. It is indicated that the inheritance of fat content was mainly controlled by the additive effect of seed embryo genes, followed by maternal additive effect and without cytoplasmic effect. Yuhua 9326 and Yongcheng Xiaomake with high fat content are superior donor parents for high fat content peanut breeding. It is essential to pay more attention to the genes expressed in pods when exploring the regulation genes for seed fat content.The accumulation effect of genes and the selection of promising haplotypes should be emphasized in the selection of hybrid progenies and the development of molecular markers.
Peanut（Arachis hypogaea L.）is an important oil and cash crop, cultivated worldwide. Sweetness is a highly heritable aspect of peanut flavor, and it is positively correlated with overall roasted peanut quality. Sweetness of peanut mainly comes from the content of sugar in peanut kernel, especially when the content of sugar is more than 6%. Therefore, increasing the sugar content in peanut kernel is the key to improving peanut flavor. However,up to now, the genetic analysis of sugar content in peanut kernel has not been reported. To investigate the genetic inheritance of sugar content in peanut, a mixed major gene plus polygene in-heritance model was employed to analyze in four generations（P1, P2, F1 and F2）of two cross combinations with high and low sugar content. The results showed that the genetic model E-0（MX2-ADI-AD）, incorporating two additive – dominance – epitasis major genes plus an additive–dominance–epitasis polygene, was the best-fitting genetic model for sugar content in peanut kernel. The heritability of the major gene in the cross combinations with high sucrose content of peanut kernel as female parent was higher（84.96% and 83.00%）, while the heritability of major gene was lower（69.52% and 60.32%）in the reverse cross combination with low sucrose content in peanut kernel; on the contrary, the heritability of polygene was lower in the orthogonal combination（14.87% and 16.75%）and higher in the reverse cross combination（3 23% and 39. 25% respectively, indicating that this trait has obvious maternal effect. These results suggested that the sugar content of peanut kernel was mainly controlled by major gene and should be selected in early populations. Therefore, our findings may provide important information for flavor quality modification of peanut and may lay the foundation for further QTL mapping.
In order to improve the efficiency of selecting elite combinations, five parental lines were selected to make 20 cross combinations by Griffing complete diallel crossing design, and 10 quality traits including contents of oil, protein, sucrose and fatty acid compositions in peanut kernel were tested to assess the combining ability and genetic parameters. Analysis of combination ability showed that Yuhua 132（W191）with high general combination ability（GCA）was the optimal lines for selecting high oil, stearic acid, linoleic acid, arachidic acid and behenic acid; Jihuatian 1（JT1）with high GCA was the optimal lines for selecting protein and sucrose; and WT08-0937（DF15）with high GCA was the optimal lines for selecting oleic acid and eicosenoic acid. Analysis of regression Wragainst Vr indicated that inheritance of 7 quality traits conformed to the additive-dominant mode, and the inheritance was mainly additive effect, while the dominant effect was small and partial dominant, which included oil, palmitic acid, stearic acid, oleic acid , linoleic acid, arachidic acid and behenic acid. Principal component analysis（PCA）was carried out for 10 traits of all hybrids, and the cumulative contribution rate of the first two principal components（Dim1 and Dim2）reached 88.6%. The results of PCA revealed that the oil content was negatively correlated with protein and sucrose content, while the oil content was weakly correlated with unsaturated fatty acid content.This study provided a theoretical basis for parents and off-spring selection in peanut breeding.
Yuhua 37, a high oleic acid peanut variety with high yield, appreciable resistance to major diseases and wide adaptability, was bred by hybridization and pedigree selection. The female parent Haihua 1 was a widely grown variety and the male parent Kaixuan 016 was the high-oleic trait donor line. The near-infrared quality analyzer and molecular marker-assisted selection approach were applied in the selection of single plants in the segregating generations. In 2012 and 2013, the variety was tested in the Henan Peanut Regional Trial for High-quality Spanish-type varieties. The average yield was 4583.55 kg/hm2 with an increase of 2.68% over the control variety Yuanza 9102 across 9 test locations in two years. In 2014, it was included in the Henan Provincial Peanut Production Test for Spanish-type variety, an average pod yield of 5084.40 kg/hm2 with an increase of 10.84% over the control Yuanza 9102 was recorded across 6 test locations. This cultivar is a small-seeded Spanish-type variety with growth duration of about 116 days when planted in the summer season in Henan province. Yuhua 37 was approved to be released by Henan province in 2015. Its genetic background and the mutation types of the two major genes controlling oleic acid content were further analyzed, which may provide some enlightenment in future development of high-oleic peanut varieties.
Studies on variety stability and genotype-environment interaction (GEI), with respect to the quality characters of peanut, which can provide reference for peanut quality breeding and variety selection in different ecological regions. In this study, five quality traits, including total oil content, oleic acid, linoleic acid, palmitic acid,and total protein content of 16 peanut cultivars, which mainly planted in Huang-Huai-Hai area, were evaluated by using GGE-bioplot with two years replication. The results showed that each quality trait exhibited high variation values (the sum of PC1 value and PC2 value), varied from 61.5% to 79.9%. The lowest variation value (61.5%) was observed in the quality of total oil content while the oleic acid content showed the highest GGE variation value (79.9%). The 16 tested peanut varieties showed stable quality trait partially during the two years, of which‘Pu 9519’had the least phenotypic variation of total oil content,‘Shanhua 9’had the least phenotypic variation of linoleic acid content,‘Kainong 49’almost with no phenotypic variation of oleic acid content,‘Tianfu 23’was considered as the most stable variety of palmitic acid content and protein content. Among the 5 regions, Xuzhou City and Puyang City were most representative of the cities in terms of the cultivation of peanuts with high oil content and oleic acid content, respectively. Meanwhile, varieties with good adaptability had also been identified under different ecological environments. Those results provide valuable references for further extension of peanut varieties.
The creation of mutants is of great significance to genetic improvement and functional genomics of peanut. In order to obtain new peanut mutant germplasm, this study explored EMS mutagenesis conditions of peanut varieties with different genotypes. It was found that the appropriate mutagenic concentrations of Huayu 22, Huayu 71, Huayu 9301, Shitouqi and Fuhuasheng were 0.4%, 0.5%, 0.3%, 0.5% and 0.3%, respectively. The analysis of bud length, plant height, root length and root number in seedling stage under the optimum concentration showed that all the 5 cultivars were able to form seedlings normally, but all were seriously damaged. On the basis of the preliminary experiment, 5000 Huayu 22 seed swas treated by 0.4% EMS solution. Both M1 and M2 generation mutants showed diversified phenotypes. For example, plant height, plant type, pod, seed kernel, branching number and leaf shape were changed. The phenotypic variation rate was 12.9%. Our work provides abundant germplasm for peanut genetics research and breeding.
Ubiquitination system is involved in many biological processes, including cell differentiation, hormone response, biological and abiotic stress response, by mediating the post-translational modification of proteins.The ubiquitination ligase containing U-box gene is one of the important enzymes in the Ubiquitination system. In this study, soybean U-box family gene Glyma. 13G115900 (GmPUB32) was cloned from soybean variety Kengfeng 16. Sequence analysis showed that GmPUB32 gene has an open reading frame with a length of 513 bp, encoding 170 amino acid with a RING/ U-box conserved domain between its 83-131 amino acids. The results of subcellular localization analysis showed that GmPUB32 protein was located in the cell membrane and cytoplasm. The expression of GmPUB32 gene in soybean root, stem, leaf and pod was detected on different levels, and it is the highest in root. Fluorescence quantitative PCR analysis showed that the expression of GmPUB32 was significantly down-regulated under salt stress. Salt stress tolerance of T3 generation of Arabidopsis thaliana overexpressing GmPUB32 were analyzed, and the results showed that the germination rate, cotyledon afforestation rate and survival rate were significantly lower than that of the wild type under salt stress, in addition, growth rate of transgenic hairy root overexpressing GmPUB32 also significantly was suppressed compared with the wild type. Therefore, GmPUB32 may play a role in response to salt stress process as a negative regulatory factors.
The Aux IAA gene family plays an important role in the development of plant shoots. In order to explore the regulatory role of Aux/IAA gene family in the development process of soybean shoots, the protein sequences of Aux/IAA gene family of Arabidopsis thaliana were used in current study as a reference to identify the Aux/IAA family genes in soybean genome. There were 63 Aux/IAA gene members in soybean genome. Then the full-length amino acid sequences of Aux/IAA family genes identified from Arabidopsis thaliana and chickpea and soybean were compared to construct an evolutionary tree. The results showed that the genetic relationship between Aux/IAA family members was significantly different, and the frequency of homologous recombination during the process of plant evolution was different. The genes were identified which expressed differentially between 594 (DN) and Charleston (CH) and between the high pool (WH) and short pool(WS) of their RIL population and the high pool (JH) and short pool (JS) of their F2 population. A total of 17 Aux/IAA genes are differential expression. There were 15 genes expressed differentially in the CHvsDN group, 2 in the JHvsJS group, and only 1 in the WHvsWS group. Furthermore,Glyma.10G180100 was differentially expressed in the JHvsJS group and the WHvsWS group. These results give a deep understanding about the Aux/IAA gene family in soybean and provide a theoretical basis for regulating the development of soybean shoots.
To explore the the effects of proper planting density on the reproductive growth and yields of peanut population, Yuanza 6, Spanish type peanut with small pod was used as the material, the changes of leaf function, photosynthetic characteristics and yields of peanuts under various combinations in summer-planting peanut were studied. The results showed that the planting model of 2.25 × 105 hole / hm2 could reduce the net photosynthetic rate, antioxidant capacity and the photosynthetic effective radiation interception rate of the middle and lower part of the population, and increase the chlorophyll content, leaf area index and the photosynthetic effective radiation interception rate of the upper part of the population, and increase the full pod rate and kernel rate compared with that in 1.8 × 105 hole/ hm2. Yields of the planting model of 2.25 × 105 hole / hm2 was 12.44% higher than that in 1.8 × 105 hole / hm2, yields of double seed was 12.47% higher than that of single seed, and yields of equal row spacing planting and wide-narrow row planting were basically the same. Yuanza 6 is a close-planting variety, which can be planted directly in summer. The planting density of the variety is increased properly, yields can be increased effectively and the commercial quality of pods can be improved.
In order to clarify the suitable phosphorus-zinc combination application mode and its possible mechanism for peanut high yield and efficiency, the field experiments was conducted to study the effects of exogenous phosphorus rates on root morphology, chlorophyll content and yield of peanut under different zinc application methods. The results showed that the phosphorus application promoted the roots and shoots growth of peanut, improved the SPAD values, and increased the yield and its components. Peanut yields under P45, P90, P135, and P180 treatments averagely increased by 36.8%, 60.7%, 48.3% and 39.2% compared with non-phosphorus (P0), respectively. The zinc application method had no significant effect on root morphological characteristics and aboveground vegetative growth of peanut, but had significant effects on the number of fruit filled per plant, fruit weight per plant, and chlorophyll content of leaves. The yield averagely increased by 6.4% and 10.1% under foliar (Znf) and soil applied Zn fertilizers (Zns), respectively, suggesting having higher yield under soil zinc application. It was observed that the root and shoot growth, yield and its components of peanut was not significantly affected by the interaction between phosphorus fertilizer and Zn application methods, the study parameters were the highest under ZnsP90 treatment. In summary, in lime concretion black soil area of peanut production, soil applied 90 kg P2O5/hm2 combined with 30 kg ZnSO4·7H2O /hm2 improved the root morphological characteristics and photosynthetic characteristics of peanut, which was a suitable phosphorus and zinc fertilizer application method for peanut growth and high yield.
To screen Al-tolerance materials on acid-soil planting areas for oilseed rape, and to investigate seedling and root traits responding to Al stress, hydroponic experiments were carried out using 81 Brassica napus varieties under AlCl3 (0 and 100 μmol·L-1) stress. Al-tolerance related indicators were comprehensively evaluated by correlation analysis, principal component analysis and cluster analysis. The indicators included root morphology, plant architecture, biomass and physiological characteristics. Results showed that Al stress had different effects on individual indicators of different genotypes at seedling stage. Six Al-resistance varieties, 65 intermediate tolerance varieties, and 10 Al-sensitive varieties were screened. Among them, roots in different diameter ranges responded differently. Root length, surface area, volume, and number of root tips of D1 type (root diameter 0.0-0.5 mm) showed the largest declines, and D3 type (root diameter> 2.0 mm) showed the smallest decrease. Root indicators of different diameters of Al-sensitive varieties were more severely inhibited by Al stress than those of Al-tolerant. Length, surface area, volume and number of root tips in D1, D2 (diameter 0.5-2.0 mm) and D3 were less than those of Al-tolerant varieties. Therefore, it is more objective to evaluate Al-tolerance varieties with comprehensive indicators. Roots with different diameter ranges of Al-tolerant varieties were less affected by Al. The tolerant varieties have stronger adaptability to Al stress by changing root morphology，and having more fine roots might be a probable mechanism against aluminum toxicity.