Genetic mapping reveals a candidate gene CmoFL1 controlling fruit length in pumpkin.

Fruit length (FL) is an important economical trait that affects fruit yield and appearance. Pumpkin (Cucurbita moschata Duch) contains a wealth genetic variation in fruit length. However, the natural variation underlying differences in pumpkin fruit length remains unclear. In this study, we constructed a F2 segregate population using KG1 producing long fruit and MBF producing short fruit as parents to identify the candidate gene for fruit length. By bulked segregant analysis (BSA-seq) and Kompetitive Allele-Specific PCR (KASP) approach of fine mapping, we obtained a 50.77 kb candidate region on chromosome 14 associated with the fruit length. Then, based on sequence variation, gene expression and promoter activity analyses, we identified a candidate gene (CmoFL1) encoding E3 ubiquitin ligase in this region may account for the variation of fruit length. One SNP variation in promoter of CmoFL1 changed the GT1CONSENSUS, and DUAL-LUC assay revealed that this variation significantly affected the promoter activity of CmoFL1. RNA-seq analysis indicated that CmoFL1 might associated with the cell division process and negatively regulate fruit length. Collectively, our work identifies an important allelic affecting fruit length, and provides a target gene manipulating fruit length in future pumpkin breeding.

Promoter variations of ClERF1 gene determines flesh firmness in watermelon.

BACKGROUND: Flesh firmness is a critical factor that influences fruit storability, shelf-life and consumer's preference as well. However, less is known about the key genetic factors that are associated with flesh firmness in fresh fruits like watermelon. RESULTS: In this study, through bulk segregant analysis (BSA-seq), we identified a quantitative trait locus (QTL) that influenced variations in flesh firmness among recombinant inbred lines (RIL) developed from cross between the Citrullus mucosospermus accession ZJU152 with hard-flesh and Citrullus lanatus accession ZJU163 with soft-flesh. Fine mapping and sequence variations analyses revealed that ethylene-responsive factor 1 (ClERF1) was the most likely candidate gene for watermelon flesh firmness. Furthermore, several variations existed in the promoter region between ClERF1 of two parents, and significantly higher expressions of ClERF1 were found in hard-flesh ZJU152 compared with soft-flesh ZJU163 at key developmental stages. DUAL-LUC and GUS assays suggested much stronger promoter activity in ZJU152 over ZJU163. In addition, the kompetitive allele-specific PCR (KASP) genotyping datasets of RIL populations and germplasm accessions further supported ClERF1 as a possible candidate gene for fruit flesh firmness variability and the hard-flesh genotype might only exist in wild species C. mucosospermus. Through yeast one-hybrid (Y1H) and dual luciferase assay, we found that ClERF1 could directly bind to the promoters of auxin-responsive protein (ClAux/IAA) and exostosin family protein (ClEXT) and positively regulated their expressions influencing fruit ripening and cell wall biosynthesis. CONCLUSIONS: Our results indicate that ClERF1 encoding an ethylene-responsive factor 1 is associated with flesh firmness in watermelon and provide mechanistic insight into the regulation of flesh firmness, and the ClERF1 gene is potentially applicable to the molecular improvement of fruit-flesh firmness by design breeding.

Pan-genome analysis sheds light on structural variation-based dissection of agronomic traits in melon crops.

Sweetness and appearance of fresh fruits are key palatable and preference attributes for consumers and are often controlled by multiple genes. However, fine-mapping the key loci or genes of interest by single genome-based genetic analysis is challenging. Herein, we present the chromosome-level genome assembly of 1 landrace melon accession (Cucumis melo ssp. agrestis) with wild morphologic features and thus construct a melon pan-genome atlas via integrating sequenced melon genome datasets. Our comparative genomic analysis reveals a total of 3.4 million genetic variations, of which the presence/absence variations (PAVs) are mainly involved in regulating the function of genes for sucrose metabolism during melon domestication and improvement. We further resolved several loci that are accountable for sucrose contents, flesh color, rind stripe, and suture using a structural variation (SV)-based genome-wide association study. Furthermore, via bulked segregation analysis (BSA)-seq and map-based cloning, we uncovered that a single gene, (CmPIRL6), determines the edible or inedible characteristics of melon fruit exocarp. These findings provide important melon pan-genome information and provide a powerful toolkit for future pan-genome-informed cultivar breeding of melon.

More Income, Less Pollution? How Income Expectation Affects Pesticide Application.

Farmers are still the foundation of China's current "small, scattered, and weak" agricultural production pattern. As such, increasing guidance for reduction response behavior is central to reducing agricultural pesticide use. Following this pesticide reduction logic, four of the most widely promoted pesticide reduction technologies, including light trapping, biopesticide application, healthy crop growth, and insect-proof net technologies, were selected, and a theoretical analysis framework of farmers' willingness to adopt these technologies was constructed based on the theories of value perception and planned behavior. An ordered logistic regression model is used to explore key factors behind current pesticide reduction technology perceptions, technology response willingness, and behavioral decisions of farmers in China, with survey data from 516 farmers in Henan Province. The results show that among the four pesticide reduction technologies, healthy crop growth technology is the most-appealing one for farmers, followed by insect-proof net technology and biopesticide application technology. The least-appealing one for farmers is the light trapping technology. Farmers' perceived degree of income improvement from technology adoption is the main determinant of their willingness, which is positively significant at a 1% confidence level in all four models. In addition, farmers' willingness to respond to technologies is also significantly influenced by farmers' perception of technical operational ability, perception of risk from adopting technology, government-related subsidies, government technical training guidance, trust in government promotion of technology, and perception of the government's role in improving the external environment for adopting technology.

[Clinical Analysis of 208 Patiets with BCR/ABL Negative Myeloproliferative Neoplasms].

OBJECTIVE: To analyze the incidence, hemogram, genetics, clinical manifestations, therapeutic efficacy and outcome of patients with myeloproliferative neoplasms(MPN) so as to provide much more therapeutic basis for clinically studying the pathogenesis, diagnosis, and treatment as well as evaluating the prognosis of MPN patients. METHODS: The clinical data and related laboratory test results in 208 cases of BCR/ABL fusion gene regative MPN were collected and analyzed retrospectively. RESULTS: The MPN could occur at any age, but the highest incidence was observed in patients aged 40-79. Among 208 patients with MPN, the patients with essential thrombocythemia(ET) accounted for 48.56%(101/208), the patients with polycythemia vera(PV) accounted for 25.96%(54/208), and the patients with primary myelofibrosis(PMF) accounted for 25.48(53/208). The clinical manifestation of MPN varied, the first manifestations was no-specific, onset of disease presented slow. The JAK2V617F gene mutation existed in 130 out of 208 patients with MPN, total mutation rate was 62.5%;JAK2V617F mutation rate in PV patients was 81.5%(44/54), while that in ET and PMF patients was 58.4%(59/101) and 50.9%(27/53) respectively, the detected rate of this mutation in PV patients was significantly higher than that in ET and PMF patients (P<0.05), while there was no significant difference between ET and PMF patients(P>0.05). In PV group, the WBC count of JAK2V617F positive patients was significantly enhanced (P<0.01), while there were no statistical differences of hemoglobin level and platelet count (P>0.05); in ET and PMF groups, the JAK2V617F positive patients had a higher WBC count and hemoglobin level(P<0.05), while the difference of platelet count was no significant(P>0.05). The most common vascular event in patients with MPN was ischemic cerebrovascular disease. The JAK2V617F mutation related with risk of thrombosis (OR=2.222, 95% CI=1.101 to 4.486). The difference in the incidence of vascular event between ET and PV patients was no statistically significant (P>0.05), but the incidence of vascular event in ET and PV patients was higher than that in PMF patients(P<0.05). The disease conversion much more easily happened in JAK2V617F positive patients. After treatment, the MPN could be controlled, yet the maintained treatment is needed. CONCLUSION: The MPN can occur almost at any age, but more commonly occures in middle-aged and elderly persons. The onset of MPN varies, the clinical manifestation was similar, a high detected rate of JAK2V617F mutation is observed in MPN patients and relates closely with onset of MPN; moreover, JAK2V617F mutation rate relates with type of MPN. The MPN patients with JAK2V617F mutation have higher WBC count and higher incidence of thrombosis. After treatment, the MPN can be better controlled, and need maintenance treatment. So as to avoid the reccurence of disease, control the complications and obtain the longterm survival.

[Clinical Significance of the Serum EPO Level in Patients with Iron Deficiency Anemia].

OBJECTIVE: To investigate the expression level of erythropoietin (EPO) and ferritin before and after treatment of patients with iron deficiency anemia (IDA) so as to explore their clinical significance in diagnosis and discrimination. METHODS: The EPO and ferritin levels in serum of 37 patients with IDA were determined by using chemiluminescence analysis (CLIA method) and electrical chemiluminescence analysis (ECLIA method), 30 healthy people were randomly selected as normal controls. RESULTS: (1) the sEPO level in IDA patients of group before treatment, group treated for 1 month and group treated for 2 months was higher than that in normal control group (P < 0.05). The level of sEPO of IDA patients in different groups after treatment was lower than that in IDA patients of groups before treatment, along with improvement of anemia status, the level of EPO was gradually reduced, and the level of sEPO in patients of group treated for 3 months was not statistical significant in comparison with that in normal control (P > 0.05). The level of ferritin in IDA patients before and after treatment was lower than that in normal control group (P < 0.05). The level of ferritin in IDA patient of groups after treatment was all higher than that in patients of groups before treatment, but comparision of serum ferritin level in patients of groups after treatment did not show statistical significance. (2) The level of logEPO in IDA patient before and after treatment was negatively related with level of Hb, but the level of ferritin in IDA patients was positively related with the level of Hb before treatment (r = 0.449, P = 0.005), the level of ferritin in patients of different group after treatment and in normal group did not related with level of HB. (3) The level of serum EPO in patients of severe anemia group was obviously higher than that in patients of moderate and mild anemia groups, and along with aggravation of anemia, the EPO level was gradually arised. CONCLUSION: The serum EPO is involved in the process of erythrocyte hematopoiesis, and can indicate the level of anemia, its sensitivity for anemia is higher than that of ferritin, and has important clinical value for evaluating status of diseases, observing therapeutic efficacy and judging prognosisi of IDA.