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51.
Summary Glume cultures of monogenic recessive mutants PGTSLS1 (Plant Genetics triticale selection large spike 1) and PGTSLG2 (Plant Genetics triticale selection long grain 2) were employed along with their parent PGTS control (Plant Genetics triticale selection control) and their F1 and F2 progenies, to determine the genetic basis of plant regeneration in hexaploid triticale. The mutant PGTSLS1 exhibited greater efficiency of plant regeneration (22.4%) followed by PGTS control (7.6%) and PGTSLG2 did not exhibit any regeneration. All the three F1's exhibited plant regeneration frequency on par with that of control (6.9–7.3%), suggesting dominant nature of control genotype over the isogenic mutants. The F2 results suggested that genetic control over the high frequency regeneration of PGTSLS1 was monogenic recessive in nature, and genetic control over the recalcitrant nature of PGTSLG2 also was monogenic recessive. The F2 of the cross PGTSLS1 × PGTSLG2 segregated into four classes. Of the 114 F2 plants, 19 showed no regeneration, 70 of them exhibited 6–8% regeneration, 20 of them 19–24% regeneration, and 5 of them exhibited highest frequency regeneration (57–60%). These observations suggest dihybrid segregation for regeneration. The highest frequency of plant regeneration (57–60%) exhibited by 5 F2 plants may be due to the interaction of non-allelic genes in recessive condition. These results clearly demonstrate the association of at least two genes with plant regeneration in hexaploid triticale. 相似文献
52.
Sukumar Saha Mehmet Karaca Johnie N. Jenkins Allan E. Zipf O. Umesh K. Reddy Ramesh V. Kantety 《Euphytica》2003,130(3):355-364
Microsatellites or Simple Sequence Repeats(SSRs) are informative molecular genetic markers in many crop species. SSRs are
PCR-based, highly polymorphic, abundant, widely distributed throughout the genome and inherited in a co-dominant manner in
most cases. Here we describe the presence of SSRs in cDNAs of cotton. Thirty one SSR primer pairs of 220 (∼14%) tested led
to PCR amplification of discrete fragments using cotton leaf cDNA as template. Sequence analysis showed 25% of 24randomly
selected cDNA clones amplified with different SSR primer pairs contained repeat motifs. We further showed that sequences from
the SSR-containing cDNAs were conserved across G. barbadense and G. hirsutum, revealing the importance of the SSR markers for comparative mapping of transcribed genes. Data mining for plant SSR-ESTs
from the publicly available databases identified SSRs motifs in many plant species,including cotton, in a range of 1.1 to4.8%
of the submitted ESTs for a given species.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
53.
Summary Semilooper resistant transgenic castor plants were produced through Agrobacterium-mediated genetic transformation method. Two castor cultivars, Jyothi and VP1 were transformed using the super-binary vector
pTOK233 carrying gus A and hpt genes. Putative transformants were regenerated following selection on the hygromycin containing medium. GUS positive primary
transformants, when subjected to Southern analysis, revealed stable integration of gus A into their genomes. In the T1 generation, a monogenic segregation ratio of 3 GUS positive: 1 GUS negative plants was observed. Furthermore, transformation
experiments were carried out with the Agrobacterium pSB111 super-binary vector carrying a synthetic delta endotoxin gene cryIAb and the herbicide resistance gene bar both driven by cauliflower mosaic virus 35S promoter. Putative transformants were regenerated through selection on the phosphinothricin
containing medium and Basta tolerant transformants were subjected to molecular analysis. PCR analysis revealed the presence
of both bar and cryIAb genes in the Basta tolerant primary transformants. Southern analysis of PCR positive plants with cryIAb probe showed a 3 Kb band upon HindIII digestion and a > 6 Kb band with BamHI digestion, thus suggesting stable integration of cryIAb intact expression cassette and independent nature of the transformants. The primary transformants subjected to ELISA disclosed
varied levels of Cry protein. These transgenics expressing cryIAb – when bioassayed against freshly hatched semilooper larvae – induced substantial (> 88%) insect mortality. Southern analysis
of 2T1 plants revealed the presence of cryIAb gene, indicating stable inheritance of the transgene into the next generation. In T1, all the Southern-positive plants for cryIAb invariably exhibited tolerance to Basta, denoting co-segregation of both bar and cryIAb genes. Transgenics, expressing cryIAb exhibited ample resistance against the castor semilooper. 相似文献
54.
L. Krishnamurthy Rachid Serraj C. Tom Hash Abdullah J. Dakheel Belum V. S. Reddy 《Euphytica》2007,156(1-2):15-24
Genetic improvement of salt tolerance is of high importance due to the extent and the constant increase in salt affected areas.
Sorghum [Sorghum bicolor (L.) Moench] has been considered relatively more salt tolerant than maize and has the potential as a grain and fodder crop
for salt affected areas. One hundred sorghum genotypes were screened for salinity tolerance in pots containing Alfisol and
initially irrigated with a 250-mM NaCl solution in a randomized block design with three replications. Subsequently 46 selected
genotypes were assessed in a second trial to confirm their responses to salinity. Substantial variation in shoot biomass ratio
was identified among the genotypes. The performance of genotypes was consistent across experiments. Seven salinity tolerant
and ten salinity sensitive genotypes are reported. Relative shoot lengths of seedlings were genetically correlated to the
shoot biomass ratios at all stages of sampling though the relationships were not close enough to use the trait as a selection
criterion. In general, the whole-plant tolerance to salinity resulted in reduced shoot Na+ concentration. The K+/Na+ and Ca2+/Na+ ratios were also positively related to tolerance but with a lesser r
2. Therefore, it is concluded that genotypic diversity exists for salt tolerance biomass production and that Na+ exclusion from the shoot may be a major mechanism involved in that tolerance. 相似文献
55.
S. Murali Mohan R. Madhusudhana K. Mathur D. V. N. Chakravarthi Sanjay Rathore R. Nagaraja Reddy K. Satish G. Srinivas N. Sarada Mani N. Seetharama 《Euphytica》2010,176(2):199-211
Forage sorghum cultivars grown in India are susceptible to various foliar diseases, of which anthracnose, rust, zonate leaf
spot, drechslera leaf blight and target leaf spot cause severe damage. We report here the quantitative trait loci (QTLs) conferring
resistance to these foliar diseases. QTL analysis was undertaken using 168 F7 recombinant inbred lines (RILs) of a cross between a female parental line 296B (resistant) and a germplasm accession IS18551
(susceptible). RILs and parents were evaluated in replicated field trials in two environments. A total of twelve QTLs for
five foliar diseases on three sorghum linkage groups (SBI-03, SBI-04 and SBI-06) were detected, accounting for 6.9–44.9% phenotypic
variance. The morphological marker Plant color (Plcor) was associated with most of the QTL across years and locations. The QTL information generated in this study will aid in
the transfer of foliar disease resistance into elite susceptible sorghum breeding lines through marker-assisted selection. 相似文献
56.
Akanksha Awasthi K. Raja Reddy Sukumar Saha Johnie N. Jenkins David M. Stelly 《Euphytica》2018,214(11):218
Limited knowledge about genetic and physiological traits associated with drought and low temperature stresses and narrow genetic diversity in Upland cotton (Gossypium hirsutum L.) are serious impediments in its genetic improvement. The objectives of this research were to determine the genetic and physiological traits associated with drought and low temperature effects and to identify chromosomal effects on these traits using chromosome substitution (CS) lines from three alien species of Gossypium, G. barbadense, G. tomentosum, and G. mustelinum, respectively. Two experiments were conducted to study low temperature and drought stress effects during seedling emergence and early growth stages in 21 cotton CS-lines with parent, Texas Marker (TM)-1. In Experiment I, plants were grown at optimum (30/22 °C) and low (22/14 °C) temperature conditions under optimum water and nutrient conditions. In Experiment II, plants were grown at optimum water (soil moisture content of 0.167 m3 m?3) and in drought (soil moisture content 0.105 m3 m?3) conditions under optimum temperature conditions. Above- and below-ground growth traits including several root traits of the CS lines were assessed at 25 days after sowing. The findings suggest which substituted chromosome or chromosome segment from the alien species likely harbors one or more genes for higher and lower tolerance to low temperature, respectively. CS-T04 and CSB08sh showed higher and lower tolerance to low temperature, respectively and CS-T04 and CS-B22sh showed higher and lower tolerance, respectively, to drought. CS lines are valuable analytical tool and useful genetic resources for targeted exploitation of beneficial genes for drought and low temperature stresses in Upland cotton. 相似文献
57.
Sameer Kumar Chanda Venkata Ganga Rao Nadigatla Veera Prabha Rama Rachit K. Saxena Kulbhushan Saxena Hari D. Upadhyaya Moses Siambi Said N. Silim Kothapally Narasimha Reddy Anupama J. Hingane Mamta Sharma Shivali Sharma Stephen Dominic Lyimo Rose Ubwe Meshack Makenge Kananji Gad Paul Kiprotich Kimurto Manuel Amane Kennedy Kanenga Yuventino Obong Emanuel Monyo Chris Ojiewo Nagesh Kumar Mallela Venkata Jaganmohan Polineni Rao Prashanthi Lakkireddy Sudhakar Chourat Indraprakash Singh Sobhan Sajja Shruthi Hirikara Beliappa Rajeev K. Varshney 《Plant Breeding》2019,138(4):445-454
In the past five decades, constant research has been directed towards yield improvement in pigeonpea resulting in the deployment of several commercially acceptable cultivars in India. Though, the genesis of hybrid technology, the biggest breakthrough, enigma of stagnant productivity still remains unsolved. To sort this productivity disparity, genomic research along with conventional breeding was successfully initiated at ICRISAT. It endowed ample genomic resource providing insight in the pigeonpea genome combating production constraints in a precise and speedy manner. The availability of the draft genome sequence with a large‐scale marker resource, oriented the research towards trait mapping for flowering time, determinacy, fertility restoration, yield attributing traits and photo‐insensitivity. Defined core and mini‐core collection, still eased the pigeonpea breeding being accessible for existing genetic diversity and developing stress resistance. Modern genomic tools like next‐generation sequencing, genome‐wide selection helping in the appraisal of selection efficiency is leading towards next‐generation breeding, an awaited milestone in pigeonpea genetic enhancement. This paper emphasizes the ongoing genetic improvement in pigeonpea with an amalgam of conventional breeding as well as genomic research. 相似文献
58.
Three sorghum cytoplasmic male sterile lines CSV4 A(V), CSV4 A(G1) and CSV4 A(M), grouped as A4, were compared with a milo (A1) and two other non-milo (A2 and A3) cytoplasms for their RFLP patterns of mitochondrial DNA (mtDNA). A 9.7 kb clone from pearl millet mtDNA discriminated each
of the three A4 entries whereas other maize and pearl millet mtDNA clones used could not distinguish this group completely. The molecular
differences within the A4 cytoplasmic group offer some explanation for the inconsistency in the fertility restoration behaviour of these A4 lines obtained with a definite set of testers in the field.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
59.
Bheema Lingeswara Reddy Inja Naga Lakshmi Narasu Mangamoori Sivaramakrishnan Subramanyam 《Journal of Crop Science and Biotechnology》2012,15(1):9-16
In recent years, microsatellites have become the most used markers for studying population genetic diversity. The increased
availability of the DNA sequences has given the possibility to develop EST-derived SSR markers. A total of 1,927 ESTs of Eleusine coracana available in the NCBI database were mined for SSRs. Di-nucleotides are the most occurring motifs accounting for more than
50% of the repeats, of which GA was the most abundant motif and tetra-nucleotides are the least occurring motifs. Of the 132
markers identified, 30 primer pairs based were synthesized. SSR markers were used for variety discrimination and genetic assessment
in 15 finger millet accessions; 20 primers showed polymorphism and 13 primers were identified as having a PIC value above
0.5. On the basis of the distribution of these polymorphic alleles, the 15 accessions were classified into two groups. This
study has demonstrated the potential of EST-derived SSR primer pairs in finger millet. These primers will serve as valuable
source for further breeding programs. 相似文献
60.