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Cao Z.,Nanjing Agricultural University | Zhu X.,Nanjing Agricultural University | Chen H.,Xinjiang Academy of Agriculture and Reclamation Science | Zhang T.,Nanjing Agricultural University
Molecular Breeding | Year: 2015

By backcrossing and self-pollinating twice, a series of improved lines (BC2F3) of cotton derived from super-quality fiber property chromosome segment introgression lines were developed by molecular marker-assisted selection (MAS). One of these improved lines, 3326-7, in the background of Xinluzao (XLZ) 41, was transferred from an introgression line (IL088-A7-3) derived from a cross between Gossypium hirsutum acc. TM-1 and G. barbadense cv. Hai7124. This line has consistently demonstrated super-quality fiber properties including fiber length, strength, and fineness. To fine-map the clustered fiber quality quantitative trait loci (QTLs), we further crossed the homozygous line 3326-7 with its recurrent parent XLZ41 to produce BC3F2, BC3F3, and BC3F4 populations. A linkage group was constructed using 1248 BC3F2 plants, and QTL analysis using the fiber qualities of 229 recombinants confirmed the existence of qFL-chr.7 for fiber length, qFS-chr.7 for fiber strength, and qFM-chr.7 for micronaire value within the introgressed region, with R2 values of 18.6, 29.4, and 26.3 %, respectively. The presence of qFL-chr.7, qFS-chr.7, and qFM-chr.7 led to an increase in fiber length and strength of approximately 2.0 mm and 3.0 cN/tex, respectively, and a decrease in micronaire of 0.8. Using substitution mapping with 229 BC3F2 recombinants and 207 BC3F3 and BC3F4 lines with informative recombination breakpoints in the target region, we anchored qFL-chr.7 for fiber length and qFS-chr.7 for strength to the same position, with a 0.36-cM interval between the two simple sequence repeat markers, NAU3735 and NAU845. Another QTL, qFM-chr.7, was mapped to the 0.44-cM interval between MGHES75 and NAU7445. These tightly linked QTLs may explain their positive relationship and have the potential to improve cotton fiber qualities through MAS. © 2015, Springer Science+Business Media Dordrecht. Source

Wu X.-D.,Yangtze University | Liu W.,Xinjiang Academy of Agriculture and Reclamation Science
Applied Mechanics and Materials | Year: 2012

Hydraulic disc brake is essential for meeting the requirements of safety and economic efficiency during drilling and work-over procedure. To address this need, we have developed a programmable logic controller controlled novel hydraulic disc brake system with capability to apply control strategy similar to anti-lock braking system for hoisting system of truck-mounted drilling rig. This paper is to investigate the complicated interaction between the work clamp and the hydraulic control system. So designers can use this model to decide which control strategies are more suitable for the disc brake. This is demonstrated by modeling the advanced hydraulic system and simulating influential factors on dynamic characteristics of hoisting system disc brake, with the application of the Advanced Modeling Environment for Simulations of Engineering Systems. The method of modeling and simulation provides a simple, effective approach to studying hydraulic disc brake for hoisting system. Source

Nie X.,Huazhong Agricultural University | Tu J.,Huazhong Agricultural University | Wang B.,Huazhong Agricultural University | Zhou X.,Xinjiang Academy of Agriculture and Reclamation Science | Lin Z.,Huazhong Agricultural University
PLoS ONE | Year: 2015

To provide a resource for cotton genetics and breeding, an interspecific hybridization between Gossypium hirsutum cv. Emian22 and G. barbadense acc. 3-79 was made. A population of 54 BILs (backcross inbred lines, BC1 F8 ) was developed with the aim of transferring G. barbadense genes into G. hirsutum in order to genetically analyze these genes' function in a G. hirsutum background and create new germplasms for breeding. Preliminary investigation of the morphological traits showed that the BILs had diverse variations in plant architecture, seed size, and fuzz color; the related traits of yield and fiber quality evaluated in 4 environments also showed abundant phenotypic variation. In order to explore the molecular diversity of the BIL population, 446 SSR markers selected at an average genetic distance of 10 cM from our interspecific linkage map were used to genotype the BIL population. A total of 393 polymorphic loci accounting for 84.4% MAF (major allele frequency) > 0.05 and 922 allele loci were detected, and the Shannon diversity index (I) was 0.417 per locus. The average introgression segment length was 16.24 cM, and an average of 29.53 segments were introgressed in each BIL line with an average background recovery of 79.8%. QTL mapping revealed 58 QTL associated with fiber quality and yield traits, and 47 favored alleles derived from the donor parent were discovered. This study demonstrated that the interspecific BIL population was enriched with much phenotypic and molecular variation which could be a resource for cotton genetics and breeding. © 2015 Nie et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source

Zhang T.,Nanjing Agricultural University | Qian N.,Nanjing Agricultural University | Zhu X.,Nanjing Agricultural University | Chen H.,Xinjiang Academy of Agriculture and Reclamation Science | And 3 more authors.
PLoS ONE | Year: 2013

Cotton is the world's leading cash crop, and genetic improvement of fiber yield and quality is the primary objective of cotton breeding program. In this study, we used various approaches to identify QTLs related to fiber yield and quality. Firstly, we constructed a four-way cross (4WC) mapping population with four base core cultivars, Stoneville 2B, Foster 6, Deltapine 15 and Zhongmiansuo No.7 (CRI 7), as parents in Chinese cotton breeding history and identified 83 QTLs for 11 agronomic and fiber quality traits. Secondly, association mapping of agronomical and fiber quality traits was based on 121 simple sequence repeat (SSR) markers using a general linear model (GLM). For this, 81 Gossypium hirsutum L. accessions including the four core parents and their derived cultivars were grown in seven diverse environments. Using these approaches, we successfully identified 180 QTLs significantly associated with agronomic and fiber quality traits. Among them were 66 QTLs that were identified via linkage disequilibrium (LD) and 4WC family-based linkage (FBL) mapping and by previously published family-based linkage (FBL) mapping in modern Chinese cotton cultivars. Twenty eight and 44 consistent QTLs were identified by 4WC and LD mapping, and by FBL and LD mapping methods, respectively. Furthermore, transmission and variation of QTL-alleles mapped by LD association in the three breeding periods revealed that some could be detected in almost all Chinese cotton cultivars, suggesting their stable transmission and some identified only in the four base cultivars and not in the modern cultivars, suggesting they were missed in conventional breeding. These results will be useful to conduct genomics-assisted breeding effectively using these existing and novel QTL alleles to improve yield and fiber qualities in cotton. © 2013 Zhang et al. Source

Yu Y.,Huazhong Agricultural University | Yu Y.,Xinjiang Academy of Agriculture and Reclamation Science | Lin Z.,Huazhong Agricultural University | Zhang X.,Huazhong Agricultural University
Pakistan Journal of Botany | Year: 2012

Based on the established SSR-based BC1 genetic linkage map, 2 genetic maps covered with 313 markers have been developed for 2 more backcross populations which was aimed to study the difference of recombination rates between male and female gametes. The total lengths of genetic maps for male and female were 4532.9cM and 4464.4cM respectively, and the average marker distances were 14.48cM and 14.26cM respectively. The results showed that there was no difference for the recombination rates between male and female gametes on the total map length and the average marker interval. There were 6 linkage groups showing significant differences between the 2 populations, which indicated that the gamete recombinant rates can only influence some chromosomes in cotton. Although a lot of marker intervals showed difference between maps, only 17 marker intervals were caused by the male and female gametes recombination rates. Further investigation showed that the male gamete mainly resulted in a longer genetic distance between markers, and increased the recombination rates; while the female gamete usually resulted in a shorter genetic distance of marker interval, and decreased the recombination rates. The present results will give us some useful instructions in cotton genetics and breeding. Source

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