CHARACTERIZATION OF GUAVA ACCESSIONS BY SSR MARKERS, EXTENSION OF THE MOLECULAR LINKAGE MAP, AND MAPPING OF QTLS FOR VEGETATIVE AND REPRODUCTIVE CHARACTERS

SummaryMicrosatellites or simple sequence repeats (SSRs) are co-dominant molecular markers. When we used fluorescent SSR markers to construct a linkage map for the female heterogametic silkworm (Bombyx mori, ZW), we found that some loci did not segregate in a Mendelian ratio of 1:1 in a backcross population. These loci segregated in a 3:1 ratio of single bands compared with double bands. Further examination of band patterns indicated that three types of SSR bands were present: two homozygotes and one heterozygote. In the beginning, we considered to discard these markers. By scoring male and female F1 individuals, we confirmed that these loci were located on the Z chromosome. Using the sex-linked visible mutation sch (K05) and its wild-type (C108), we constructed an F1 male backcross (BC1M) mapping population. The combination of sch backcross and SSR data enabled us to map the SSR markers to the Z chromosome. By adjusting input parameters based on these data, we were able to use Mapmaker software to construct a linkage map. This strategy takes advantage of co-dominant markers for positional cloning of genes on the Z chromosome. We localized sch to the Z chromosome relative to six SSR markers and one PCR marker, covering a total of 76·1 cM. The sch mutation is an important sex-linked visible mutation widely used in breeding of commercial silkworms (e.g. male silkworm selection rearing). Localization of the sch gene may prove helpful in cloning the gene and developing strains for marker-assisted selection in silkworm breeding.

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Characterization of Mehsana Buffaloes in India

Animal Genetic Resources Information ◽

10.1017/s101423390000136x ◽

2000 ◽

Vol 28 ◽

pp. 53-62 ◽

Cited By ~ 5

Author(s):

R.K. Pundir ◽

G. Sahana ◽

N. K. Navani ◽

P.K. Jain ◽

D.V. Singh ◽

...

Keyword(s):

Management Practices ◽

Animal Husbandry ◽

Progeny Testing ◽

Health Coverage ◽

Service Period ◽

Breed Improvement ◽

Microsatellite Dna Marker ◽

North Gujarat ◽

Reproductive Characters

SummaryMehsana buffalo is distributed in Mehsana, Banaskantha and Sabarkantha districts of North Gujarat in India. The animals are reared for milk production. The management practices in the breeding tract were studied. The physical, production and reproductive characters were recorded. The Dudhsagar Research and Development Association located in Mehsana district has undertaken breed improvement programmes in farmers'herds by running field progeny testing and providing other animal husbandry services like artificial insemination, health coverage, etc. This has resultedin the improvement in the reproductive performance as is evident from the decreasein the average first service period by 74 days and the average first calving interval by 103 days from 1989 to 1997. Microsatellite DNA marker analysis was carried out on 25 Mehsana buffalo DNA samples using seven markers for genetic characterization of the breed. Number of alleles at different loci ranged from four to seven and heterozygosity ranged from 0.40 to 0.92.

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SSR based molecular profiling of elite cultivars of basmati rice (Oryza sativa L.)

Research Journal of Biotechnology ◽

10.25303/1612rjbt5563 ◽

2021 ◽

Vol 16 (12) ◽

pp. 55-63

Author(s):

Ashwani Yadav ◽

Anubhuti Sharma ◽

Ashwani Kumar ◽

Renu Yadav ◽

Rajendra Kumar

Keyword(s):

Ssr Markers ◽

Oryza Sativa L ◽

Research Work ◽

Similarity Coefficient ◽

Basmati Rice ◽

Bank Management ◽

Genomic Study ◽

Leaf Tissues ◽

Maximum Similarity

The experiment was conducted to assess the available genetic variability amongst Indian Basmati rice and identify co-dominant and reproducible robust simple sequence repeat markers for drought resistance and their utilization in marker assisted selection for developing drought resistant / tolerant aromatic rice cultivars in various parts of India as well as in world. DNA was isolated from fresh and young leaf tissues of 35 cultivars of basmati rice using the CTAB procedure of Doyle and Doyle with slightly modifications. The DNA was further quantified by spectrophotometer at 260 nm and 280 nm. The quality and quantity of DNA were checked by agarose gel electrophoresis. Out of 60 SSR markers, 18 were found to be polymorphic and the rest 42 primers were monomorphic. One of the main purposes of SSR markers in genomic study is the characterization of genetic resources to help gene bank management. The informative (18) SSR markers were capable to discriminate the entire cultivars of basmati rice used in this research work. A total of 52 alleles at 18 loci could be scored. The allelic richness per locus diversified from 2 to 5 with an average of 2.89 alleles per locus. The amplitude of Polymorphism Information Content (PIC) value is 0.066 (RM 1068) to 0.730 (RM 1059) with an average of 0.505. The Jaccard’s similarity coefficient ranged from 0.79 to 0.95. Polymorphic finding content showed a positive correlation (r =0.69) with number of alleles at the SSR locus. However it is recommended that SSR markers can be efficiently utilized for this purpose. The maximum similarity coefficient was observed between Jeerakasab and Kalanamak with a coefficient value of 95% and the minimum similarity was found between Jeerakasab and Pusa basmati-1 with a coefficient value of 79%.

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Molecular characterization of some selected persimmon genotypes and cultivars by srap and ssr markers

Genetika ◽

10.2298/gensr1702693p ◽

2017 ◽

Vol 49 (2) ◽

pp. 693-704

Author(s):

Hasan Pinar ◽

Ercan Yildiz ◽

Mustafa Kaplankiran ◽

Celil Toplu ◽

Mustafa Unlu ◽

...

Keyword(s):

Ssr Markers ◽

Clonal Propagation ◽

Genetic Relationships ◽

The Other ◽

Diospyros Kaki ◽

Ssr Primers ◽

Similarity Ratio ◽

Polymorphic Bands ◽

Dna Primers

In this study, SRAP and SSR markers were employed to determine genetic relationships among 42 persimmon genotypes (Diospyros kaki Thunb) obtained from Hatay province and 3 persimmon cultivars, 2 of which belong to Diospyros kaki Thunb and one belongs to Diospyros oleifera Cheng. Genetic relationships were determined by using a total of 29 molecular DNA primers (SRAP and SSR). Of these primers, 21 SRAP primer combinations produced a total of 107 bands and 77.6% of them were polymorphic; 8 SSR primers produced 26 polymorphic bands with an average polymorphism ratio of 84.6%. The SRAP and SSR markers produced 4.6 bands as average and the number of bands produced per marker was calculated as 3.6. The lowest similarity was observed between MK-113 (Diospyros oleifera Cheng) and the other genotypes all belongs to Diospyros kaki Thunb (with similarity ratios of 0.41-0.69 for SRAP primers, between 0.25-0.67 for SSR primers). The genotypes/cultivars belongs to Diospyros kaki had similarity ratio between 0.98-1.00 according to SRAP and SSR markers. This synonym or similarity could be results of clonal propagation rather than autogamy.

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