Home About us Contact
|
Home About us Contact | ||
|
|
||
Male-sterile Lines (male-sterile + line)
Selected AbstractsGenotyping the Heading Date of Male-Sterile Rice Line II-32AJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 4 2006Jun-Feng Xu Abstract II-32A, an elite male-sterile line of rice (Oryza sativa L.), has been widely used for the production of hybrid rice seed in China. Heading date in most combinations using II-32A shows transgressive inheritance or similarity to the latter parent, but the genotype of II-32A with respect to major genes for heading time is unknown. This limits the further exploitation of this sterile line in breeding and hybrid seed production. Using a number of major gene heading date isogenic lines and heading date QTL near-isogenic lines, we genetically analyzed II-32B under both long- and short-day conditions. We show that II-32B carries two photoperiod-sensitive genes, E1 and E3, a recessive late-heading gene, ef-1, and a photoperiod-sensitive allele, Se-1u. In addition we identified in II-32B a recessive inhibitor for E1 or Se-1n and other modified photoperiod-sensitive genes. The heading-date constitution of II-32A was determined to be E1e2E3Se-1uef-1i-Se-1. (Managing editor: Li-Hui Zhao) [source] Development of dominant nuclear male-sterile lines with a blue seed marker in durum and common wheatPLANT BREEDING, Issue 1 2001N. Tian Abstract In order to develop genie male-sterile lines with a blue seed marker, male-sterile plants, controlled by a dominant nuclear gene Ms2, were used as female parents against a 4E disomic addition line ,Xiaoyan Lanli'(2n= 44, AABBDD+4EII) as the male parent to produce monosomic addition lines with blue seed. Male-sterile plants from the monosomic addition lines were pollinated with durum wheat for several generations and in 1989 a male-sterile line with the blue grain gene and the male-sterile gene Ms2 on the same additional chromosome was detected and named line 89-2343. Using this line, the blue seed marker was successfully added to a short male-sterile line containing Ms2 and Rht10. The segregation ratios of male sterility and seed colour as well as the chromosome figurations of different plants indicated that the blue grain genes, Ms2 and Rht10 were located on the same additional chromosome. Cytological analysis showed that the blue marker male-sterile lines in durum wheat and common wheat were monosomic with an additional chromosome 4E. The inheritance ratio for blue seed male-sterile plants and white seed male-fertile plants was 19.7% and 80.3%, respectively, in common wheat. The potential for using blue marker sterile lines in population improvement and hybrid production is discussed. [source] A unique introgression from Moricandia arvensis confers male fertility upon two different cytoplasmic male-sterile lines of Brassica junceaPLANT BREEDING, Issue 2 2005S. R. Bhat Abstract A Brassica juncea line carrying an introgression from Moricandia arvensis restored male fertility to two cytoplasmic male-sterile (CMS) B. juncea lines carrying either M. arvensis or Diplotaxis catholica cytoplasm. Genetics of fertility restoration was studied in the F1, F2, F3 and backcross generations of the cross between CMS and fertility-restorer lines. No male-sterile plants were found in F1-F3 generations of the cross between CMS [M. arvensis] B. juncea and the restorer. However, a 1: 1 segregation for male sterility and fertility was observed when the F1 was pollinated with non-restorer pollen from a euplasmic line. These results clearly show that restoration is mono-genic and gametophytic. In CMS lines carrying D. catholica cytoplasm, the restorer conferred male fertility to the F1 and showed 3: 1 and 1: 1 segregations for male fertility and sterility in F2 and BC1 generations, respectively, indicating a monogenic, sporophytic mode of fertility restoration. The results were also supported by pollen stainability in the F1 which was about 65% in M. arvensis-based CMS and >90% in D. catholica-based CMS. The above results are discussed in the light of previous molecular studies which showed association between CMS and atpA in both systems. [source] Development of dominant nuclear male-sterile lines with a blue seed marker in durum and common wheatPLANT BREEDING, Issue 1 2001N. Tian Abstract In order to develop genie male-sterile lines with a blue seed marker, male-sterile plants, controlled by a dominant nuclear gene Ms2, were used as female parents against a 4E disomic addition line ,Xiaoyan Lanli'(2n= 44, AABBDD+4EII) as the male parent to produce monosomic addition lines with blue seed. Male-sterile plants from the monosomic addition lines were pollinated with durum wheat for several generations and in 1989 a male-sterile line with the blue grain gene and the male-sterile gene Ms2 on the same additional chromosome was detected and named line 89-2343. Using this line, the blue seed marker was successfully added to a short male-sterile line containing Ms2 and Rht10. The segregation ratios of male sterility and seed colour as well as the chromosome figurations of different plants indicated that the blue grain genes, Ms2 and Rht10 were located on the same additional chromosome. Cytological analysis showed that the blue marker male-sterile lines in durum wheat and common wheat were monosomic with an additional chromosome 4E. The inheritance ratio for blue seed male-sterile plants and white seed male-fertile plants was 19.7% and 80.3%, respectively, in common wheat. The potential for using blue marker sterile lines in population improvement and hybrid production is discussed. [source] Ovary colonization by Claviceps africana is related to ergot resistance in male-sterile sorghum linesPLANT PATHOLOGY, Issue 5 2003B. Komolong Ergot, caused by Claviceps africana, has emerged as a serious threat to sorghum hybrid seed production worldwide. In the absence of gene-for-gene-based qualitative resistance in commercial cultivars, varieties with high pollen production that can escape ergot infection are preferred. Recent demonstration of differences in ergot susceptibility among male-sterile lines has indicated the presence of partial resistance. Using chitin-specific fluorescin-isothiocyanate-conjugated wheat germ agglutin and callose-specific aniline blue, this study investigated the process of sorghum ovary colonization by C. africana. Conidia germinated within 24 h after inoculation (a.i.); the pathogen was established in the ovary by 79 h a.i., and at least half of the ovary was converted into sphacelial tissue by 120 h a.i. Changes in fungal cell wall chitin content and strategic callose deposition in the host tissue were associated with penetration and invasion of the ovary. The rate of ovary colonization differed in three male-sterile lines that also differed in ergot susceptibility. This work demonstrates a possible histological basis for partial resistance in male-sterile sorghum lines that could lay the foundation for variety improvement through further breeding and selection. [source] Expression levels of meristem identity and homeotic genes are modified by nuclear,mitochondrial interactions in alloplasmic male-sterile lines of Brassica napusTHE PLANT JOURNAL, Issue 5 2005Rita Teresa Teixeira Summary Homeotic conversions of anthers were found in cytoplasmic male sterile (CMS) plants of Brassica napus derived from somatic hybrids of B. napus and Arabidopsis thaliana. CMS line flowers displayed petals reduced in size and width and stamens replaced by carpelloid structures. In order to investigate when these developmental aberrations appeared, flower development was analysed histologically, ultrastructurally and molecularly. Disorganized cell divisions were detected in the floral meristems of the CMS lines at stage 4. As CMS is associated with mitochondrial aberrations, ultrastructural analysis of the mitochondria in the floral meristems was performed. Two mitochondrial populations were found in the CMS lines. One type had disrupted cristae, while the other resembled mitochondria typical of B. napus. Furthermore, expression patterns of genes expressed in particular floral whorls were determined. In spite of the aberrant development of the third whorl organs, BnAP3 was expressed as in B. napus during the first six stages of development. However, the levels of BnPI were reduced. At later developmental stages, the expression of both BnAP3 and BnPI was strongly reduced. Interestingly the expression levels of genes responsible for AP3 and PI activation such as LFY, UFO and ASK1 were higher in the CMS lines, which indicates that activation of B-genes in the CMS lines does not occur as in B. napus. Disrupted and dysfunctional mitochondria seem to be one of the first aberrations manifested in CMS which result in a retrograde influence of the expression levels of genes responsible for the second and third whorl organ differentiation. [source] | ||||||||||