Screening and Evaluation of Initial Clonal Generations of Potato Hybrids for Yield and Yield Attributing Characters

A field experiment was conducted during Rabi 2015-16 and 2016-17 at ICAR-Central Potato Research Station, Patna Bihar. In this experiment F1 with initial clonal generations viz F1C1, F1C2 and F1C3 were evaluated. The screening and selection of these generations were done in randomized block design for the character like early bulking, tuber size, tuber shape, depth of eye, tuber colour and resistance to late blight of potato etc. A total of 12,360 True Potato Seeds of 17 successful crosses and 7,322 True Potato Seeds of 23 successful crosses were sown and seedlings were transplanted, out of these 610 and 187 clones were selected during 2015-16 and 2016-17 respectively. Large number of potato cultures were planted for further evaluation in next generations. In F1C3 the cultures were planted along with more than six check varieties of potato. Cultures were evaluated and selected considering total tuber yield, shape, colour and disease reactions for further evaluation in PYT.

Mineral content of red skinned potatoes of Eastern India

Potato tuber colour is an important factor that influences consumer preferences. Eastern plain region of India contributes about 50% of total potato acreage and production. Consumers in this region generally prefer red skinned varieties. Growing awareness for nutrient rich food can create a niche market for nutritious potatoes. Potato is crop of choice for mineral biofortification owing to better mineral bioavailability due to its high ascorbic acid and minimal phytate content. Iron and zinc are the essentially required minerals for good health. Considering the nutritional importance of these elements and wider prevalence of their deficiency in Indian sub-continent, thirteen Eastern regions red skinned advanced hybrids and varieties were evaluated to find the genetic diversity for iron and zinc content. A significant wide range of contents was observed for both the elements. High heritability of both mineral suggests feasibility of selecting genotypes for breeding nutrient rich varieties. Identified genotypes can be utilised as parental lines for future breeding programme and can be released as nutrient rich potato variety.

Dihaploid induction ability of three clones of Solanum phureja (2n = 2x = 24) in interploidy cross with S. tuberosum (2n = 4x = 48)

Potato, Solanum tuberosum L. (2n = 4x = 48), is an autotetraploid species, the breeding of which at the tetraploid level is complicated by tetrasomic inheritance. Dihaploids (2n = 2x = 24) from the tetraploid cultivated potato have great potential for breeding and genetic studies. The common method deployed to obtain potato dihaploids is to make interspecific-interploidy (4x × 2x) crosses between a tetraploid seed parent and special clones from the diploid S. phureja as pollinator. Pollinators carrying a marker gene have been used, but unfortunately, these clones were very weak, with rare flowering and low male fertility under the given conditions. To find a suitable pollinator, three clones were selected from S. phureja based on flowering, pollen shed and male fertility and were crossed with five cultivated tetraploid potatoes to evaluate their dihaploid induction ability. A total of 1529 interploidy crosses were made, resulting in 1116 berries and 1456 seeds. The progeny were divided into two groups based on stem, flower and tuber colour: hybrids and non-hybrids (putative dihaploids). Chromosome counting in non-hybrid genotypes detected 39 dihaploids. The clone phu 3 and cv. Picasso, with 12.1 and 10.7 dihaploids per 100 berries, respectively, were the best dihaploid inducer and seed parent for dihaploid production.