R. K. Birhman

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Although the heritable nature of plant tissue culture responses is now well documented in many species, only a few studies have been conducted to elucidate complete inheritance patterns. Genetic control of in vitro shoot regeneration from leaf explants was investigated inSolanum chacoense using parental, F1 and F2 generations. Broad-sense heritability(More)
An F1 population consisting of 51 genotypes, derived from two unresponsive parental lines ofSolanum chacoense Bitt., was examined for shoot regeneration from leaf explants. Fourteen genotypes failed to respond whereas, among the responsive genotypes, four produced multiple shoots on over 90% of the explants. Estimates of broad-sense heritability were high(More)
To develop inbred lines from self-incompatible, cultivated diploid potatoes, an S-locus inhibitor (Sli) gene derived from a self-compatible variant of a wild potato species, Solanum chacoense, was incorporated into various cultivated diploid potatoes. The progeny was selfed twice by the action of the Sli gene to obtain 74 S2 inbred clones belonging to 8(More)
In a field study simulating commercial practice, the performance of 4x meiotic tetraploids from 4x−2x crosses (Group Tuberosum×(Group Phureja×haploid Group Tuberosum), and their 4x and 2x parents, was studied for total yield, total number of tubers, number of marketable tubers and average tuber weight. Some of the families showed striking heterotic effects(More)
As the exploitation of economic characters in potato is reaching a plateau, use of exotic germplasm offers an ideal opportunity for further improvement. Fifty-five accessions from eleven countries were studied under long and short day conditions. Wide variation was noticed for a number of phenological, morphological and tuber characters. Analysis of(More)
Unlike tuberosum, andigena potato germ plasm exhibits a high degree of genetic variation in morphological, biochemical and reproductive traits. Sixty-five percent of the 565 genotypes comprising 145 accessions of Solanum tuberosum ssp. andigena obtained from Argentina, Bolivia, Chile, Colombia and Peru remain totally vegetative and never develop any floral(More)
Tuber yield, dry matter and true protein content were studied in 24 andigena potato genotypes. Their performance and response differed greatly and significantly when grown at three levels of inorganic N, P and K fertilizer application. In general, tuber yield and protein content increased with increased fertilizer level, whereas dry matter content initially(More)
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