scholarly journals qRf8-1, a Novel QTL for the Fertility Restoration of Maize CMS-C Identified by QTL-seq

2020 ◽  
Vol 10 (7) ◽  
pp. 2457-2464
Author(s):  
Mingmin Zheng ◽  
Tian Yang ◽  
Xiaowei Liu ◽  
Guihua Lü ◽  
Peng Zhang ◽  
...  

C-type cytoplasmic male sterility (CMS-C), one of the three major CMS types in maize, has a promising application prospect in hybrid seed production. However, the complex genetic mechanism underlying the fertility restoration of CMS-C remains poorly understood. The maize inbred line A619 is one of the rare strong restorer lines carrying the restorer gene Rf4, but different fertility segregation ratios are found in several F2 populations derived from crosses between isocytoplasmic allonucleus CMS-C lines and A619. In the present study, the segregation ratios of fertile to sterile plants in the (CHuangzaosi × A619) F2 and BC1F1 populations (36.77:1 and 2.36:1, respectively) did not follow a typical monogenic model of inheritance, which suggested that some F2 and BC1F1 plants displayed restored fertility even without Rf4. To determine the hidden locus affecting fertility restoration, next-generation sequencing-based QTL-seq was performed with two specific extreme bulks consisting of 30 fertile and 30 sterile rf4rf4 individuals from the F2 population. A major QTL related to fertility restoration, designated qRf8-1, was detected on the long arm of chromosome 8 in A619. Subsequently, qRf8-1 was further validated and narrowed down to a 17.93-Mb genomic interval by insertion and deletion (InDel) and simple sequence repeat (SSR) marker-based traditional QTL mapping, explaining 12.59% (LOD = 25.06) of the phenotypic variation. Thus, using genetic analyses and molecular markers, we revealed another fertility restoration system acting in parallel with Rf4 in A619 that could rescue the male sterility of CHuangzaosi. This study not only expands the original fertility restoration system but also provides valuable insights into the complex genetic mechanisms underlying the fertility restoration of CMS-C.

2021 ◽  
Vol 12 ◽  
Author(s):  
Yaming Cai ◽  
Zhishen Ma ◽  
Collins Otieno Ogutu ◽  
Lei Zhao ◽  
Liao Liao ◽  
...  

Male sterility is an important agronomic trait for hybrid vigor utilization and hybrid seed production, but its underlying mechanisms remain to be uncovered. Here, we investigated the mechanisms of male sterility in peach using a combined cytology, physiology, and molecular approach. Cytological features of male sterility include deformed microspores and tapetum cells along with absence of pollen grains. Microspores had smaller nucleus at the mononuclear stage and were compressed into belts and subsequently disappeared in the anther cavity, whereas tapetum cells were swollen and vacuolated, with a delayed degradation to flowering time. Male sterile anthers had an ROS burst and lower levels of major antioxidants, which may cause abnormal development of microspores and tapetum, leading to male sterility in peach. In addition, the male sterility appears to be cytoplasmic in peach, which could be due to sequence variation in the mitochondrial genome. Our results are helpful for further investigation of the genetic mechanisms underlying male sterility in peach.


2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Surendra Pratap Singh ◽  
Sudhir P. Singh ◽  
Tripti Pandey ◽  
Ram Rakshpal Singh ◽  
Samir V. Sawant

Genome ◽  
2003 ◽  
Vol 46 (5) ◽  
pp. 792-797 ◽  
Author(s):  
H S Janeja ◽  
S K Banga ◽  
P B Bhaskar ◽  
S S Banga

A cytoplasmic male sterility (CMS) system for Brassica napus (2n = 38; AACC) was developed by backcross substitution of its nucleus into the cytoplasm of a wild crucifer, Enarthrocarpus lyratus. Male sterility was complete, stable, and expressed in small flowers with rudimentary anthers. Since the B. napus germplasm lines were complete or partial maintainers of male sterility, the required fertility restorer gene (Rfl) was introgressed from the cytoplasm donor species. Inheritance studies carried out on F1 and F2 populations derived from hybridizing cytoplasmic male sterile and male fertile near-isogenic (PNILs) lines of B. napus 'Westar', revealed a monogenic dominant control for fertility restoration. Bulked segregant analysis with 215 RAPD primers helped in the identification of putative primers associated with fertility restoration. Co-segregation analysis of eight such primers with Rfl gene revealed two markers, OPK 15700 and OPZ 061300, which flank the Rfl locus on either side at a distance of 8.2 and 2.5 cM, respectively. These DNA markers will be useful in marker-assisted selection for improving the commercial potential of this newly developed CMS-fertility-restorer system for hybrid seed production programs in rapeseed.Key words: oilseed rape, hybrids, cytoplasmic male sterility, fertility restoration, RAPD mapping.


Genome ◽  
1989 ◽  
Vol 32 (6) ◽  
pp. 1044-1047 ◽  
Author(s):  
G. H. Fang ◽  
P. B. E. McVetty

The inheritance of male fertility restoration for the pol cytoplasmic male sterility (CMS) system in summer rape (Brassica napus L.) was determined. Male fertility:sterility segregation ratios observed in F2 and backcross generations derived from crosses and backcrosses between two pol CMS A lines and the male fertility restorer gene(s) sources Italy and UM2353 were used in this study. Italy and UM2353 were found to possess a single Mendelian dominant gene with high male fertility restoration capabilities for the pol CMS system. Tests for allelism of the restorer genes were also conducted using male fertility:sterility segregation ratios observed in F3 families derived from crosses between F1 plants containing genes for male fertility restoration from the Italy and UM2353 restorer gene sources. The male fertility restorer gene from Italy (designated Rfp1) was found to be different (i.e., nonallelic) from the restorer gene possessed by UM2353 (designated Rfp2).Key words: Brassica napus L., oilseed rape, male fertility restoration, pol cytoplasmic male sterility.


2021 ◽  
Vol 22 (12) ◽  
pp. 6388
Author(s):  
Miaomiao Hao ◽  
Wenlong Yang ◽  
Weiwen Lu ◽  
Linhe Sun ◽  
Muhammad Shoaib ◽  
...  

Heterosis utilization is very important in hybrid seed production. An AL-type cytoplasmic male sterile (CMS) line has been used in wheat-hybrid seed production, but its sterility mechanism has not been explored. In the present study, we sequenced and verified the candidate CMS gene in the AL-type sterile line (AL18A) and its maintainer line (AL18B). In the late uni-nucleate stage, the tapetum cells of AL18A showed delayed programmed cell death (PCD) and termination of microspore at the bi-nucleate stage. As compared to AL18B, the AL18A line produced 100% aborted pollens. The mitochondrial genomes of AL18A and AL18B were sequenced using the next generation sequencing such as Hiseq and PacBio. It was found that the mitochondrial genome of AL18A had 99% similarity with that of Triticum timopheevii, AL18B was identical to that of Triticum aestivum cv. Chinese Yumai. Based on transmembrane structure prediction, 12 orfs were selected as candidate CMS genes, including a previously suggested orf256. Only the lines harboring orf279 showed sterility in the transgenic Arabidopsis system, indicating that orf279 is the CMS gene in the AL-type wheat CMS lines. These results provide a theoretical basis and data support to further analyze the mechanism of AL-type cytoplasmic male sterility in wheat.


2020 ◽  
Vol 181 (3) ◽  
pp. 171-180
Author(s):  
I. N. Anisimova ◽  
A. G. Dubovskaya

Development of heterotic hybrids is the most efficient approach to solve the problem of increasing the yield of rapeseed (Brassica napus L.), a leading oilseed crop. The cytoplasmic male sterility (CMS), widely used in rapeseed hybrid seed production, makes it possible to control hybridization between female and male lines. A review of publications on the nature of CMS systems in rapeseed and their utilization in breeding is presented. In rapeseed there are more than 10 known CMS systems of alloplasmic and homoplasmic origin. The male sterility character proved to be determined by chimeric mitochondrial genes, characterized by the presence of novel transcribed open reading frames (orf). Mitochondrial CMS genes associated with nap, pol, ogu and Nsa sterility types as well as nuclear Rf genes for pollen fertility restoration were identified. Molecular marker systems for identification of CMS-inducing and male fertility restoring genes were developed. The ogu, pol, MSL and inap CMS systems are commonly used for producing industrial rapeseed hybrids. The State Register of the Russian Federation for 2019 contains rapeseed hybrids of only foreign origin. Main achievements in domestic rapeseed hybrid production are highlighted. Research and breeding institutions developed new source material for rapeseed hete rotic hybrid breeding in various regions of the country. The sterility and fertility restoration sources were received from Canadian and French institutions as well as from domestic working collections. The yield structure traits did not deteriorate after transferring hybrid maternal lines to the sterile cytoplasm, while the glucosinolate content increased when pollen fertility restoring genes were transferred into paternal lines. Dihaploid (androclinium) lines and in vitro culture of unfertilized ovules were used to accelerate the breeding process. Experimental hybrids were developed using pol and ogu CMS.


2019 ◽  
Vol 20 (22) ◽  
pp. 5530
Author(s):  
Bingbing Zhang ◽  
Xuexian Zhang ◽  
Meng Zhang ◽  
Liping Guo ◽  
Tingxiang Qi ◽  
...  

The cytoplasmic male sterility (CMS)/restorer-of-fertility system is an important tool to exploit heterosis during commercially hybrid seed production. The importance of long noncoding RNAs (lncRNAs) in plant development is recognized, but few analyses of lncRNAs during anther development of three-line hybrid cotton (CMS-D2 line A, maintainer line B, restorer-of-fertility line R) have been reported. Here, we performed transcriptome sequencing during anther development in three-line hybrid cotton. A total of 80,695 lncRNAs were identified, in which 43,347 and 44,739 lncRNAs were differentially expressed in A–B and A–R comparisons, respectively. These lncRNAs represent functional candidates involved in CMS and fertility restoration. GO analysis indicated that cellular hormone metabolic processes and oxidation–reduction reaction processes might be involved in CMS, and cellular component morphogenesis and small molecular biosynthetic processes might participate in fertility restoration. Additionally, 63 lncRNAs were identified as putative precursors of 35 miRNAs, and quantitative reverse transcription polymerase chain reaction (qRT-PCR) showed a similar expression pattern to RNA-seq data. Furthermore, construction of lncRNA regulatory networks indicated that several miRNA–lncRNA–mRNA networks might be involved in CMS and fertility restoration. Our findings provide systematic identification of lncRNAs during anther development and lays a solid foundation for the regulatory mechanisms and utilization in hybrid cotton breeding.


2019 ◽  
Author(s):  
Bingbing Zhang ◽  
Xuexian Zhang ◽  
Meng Zhang ◽  
Liping Guo ◽  
Tingxiang Qi ◽  
...  

Abstract Background Hybrid cotton has greatly contributed to global increase in cotton productivity. The cytoplasmic male sterility (CMS)/restorer-of-fertility system is an important tool to exploit heterosis because it is convenient for commercial hybrid seed production. The importance of long noncoding RNAs (lncRNAs) in plant development is recognized, few analyses of lncRNAs during anther development of three-line hybrid cotton (CMS-D2 line A, maintainer line B, restorer-of-fertility line R) have been reported. Results Here, we performed transcriptome sequencing during anther development in Upland cotton carrying cytoplasmic male sterile Gossypium harknessii (D2) cytoplasm. Totally 80,695 lncRNAs were identified, in which 43,347 and 44,739 lncRNAs were differentially expressed in A–B and A–R comparisons, respectively. These lncRNAs represent functional candidates involved in CMS and fertility restoration. Gene ontology enrichment analysis indicated that cellular hormone metabolic processes and oxidation–reduction reaction processes might be involved in CMS, and cellular component morphogenesis and small molecular biosynthetic processes might participate in fertility restoration. Analysis of the putative relationship between lncRNAs and miRNAs revealed that 63 lncRNAs were identified as putative precursors of 35 miRNAs, and qRT-PCR analysis showed a similar expression pattern to that of RNA-sequencing data. Furthermore, construction of lncRNA regulatory networks indicated that several miRNA–lncRNA–mRNA networks might be involved in CMS and fertility restoration. Conclusion Our findings provide systematic identification of lncRNAs during anther development and lays a solid foundation for future investigation of the regulatory molecular mechanisms and utilization in ­­breeding of hybrid cotton.


HortScience ◽  
1996 ◽  
Vol 31 (1) ◽  
pp. 123-126 ◽  
Author(s):  
X.P. Zhang ◽  
B.B. Rhodes ◽  
W.V. Baird ◽  
H.T. Skorupska ◽  
W.C. Bridges

Hybrid seed production can be facilitated by using male sterility coupled with a seedling marker. This research was initiated to combine the ms male sterility and dg delayed-green seedling marker into watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] lines. Male-sterile plants of the male-sterile line G17AB were crossed with plants of delayed-green breeding line Pale90, which has yellow cotyledons and pale-green, newly developed, true leaves. The double-recessive recombinants, male sterile and delayed green, from the F2 population were backcrossed to the male-fertile plants of G17AB. The pedigree method was used for selection in the progenies. The segregation ratios obtained from F2 and BC1F2 populations suggest that the male-sterile and delayed-green traits are inherited independently and that delayed green is inherited as a single recessive nuclear gene. Two male-sterile watermelon lines with delayed-green seedling marker have been developed. These lines will provide a convenient way to introduce male sterility and the delayed-green seedling marker into various genetic backgrounds. These two lines can be used for testing the efficiency of a new, hybrid, watermelon, seed production system.


Author(s):  
Hiroshi Yamagishi ◽  
Megumi Jikuya ◽  
Kanako Okushiro ◽  
Ayako Hashimoto ◽  
Asumi Fukunaga ◽  
...  

AbstractCytoplasmic male sterility (CMS) observed in many plants leads defect in the production of functional pollen, while the expression of CMS is suppressed by a fertility restorer gene in the nuclear genome. Ogura CMS of radish is induced by a mitochondrial orf138, and a fertility restorer gene, Rfo, encodes a P-type PPR protein, ORF687, acting at the translational level. But, the exact function of ORF687 is still unclear. We found a Japanese variety showing male sterility even in the presence of Rfo. We examined the pollen fertility, Rfo expression, and orf138 mRNA in progenies of this variety. The progeny with Type H orf138 and Rfo showed male sterility when their orf138 mRNA was unprocessed within the coding region. By contrast, all progeny with Type A orf138 were fertile though orf138 mRNA remained unprocessed in the coding region, demonstrating that ORF687 functions on Type A but not on Type H. In silico analysis suggested a specific binding site of ORF687 in the coding region, not the 5′ untranslated region estimated previously, of Type A. A single nucleotide substitution in the putative binding site diminishes affinity of ORF687 in Type H and is most likely the cause of the ineffectiveness of ORF687. Furthermore, fertility restoration by RNA processing at a novel site in some progeny plants indicated a new and the third fertility restorer gene, Rfs, for orf138. This study clarified that direct ORF687 binding to the coding region of orf138 is essential for fertility restoration by Rfo.


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