Genetic base of Indian potato selections as revealed by pedigree analysis

Abstract

Pedigree analysis of the 77 advanced Indian potato selections showed that their origin could be traced to only 49 ancestors out of which 29 were exotic, which accounted for 69.52% of the total genomic constitution and maximum contribution (40.65%) was by 10 ancestors from U.K. Breeders' tendency was to involve adapted advanced clones as immediate parents. Coefficient of relationship between pair of selections ranged from 0 to 0.68. The success of the parents used was not related to region-specific choice of parents. The findings are discussed in the context of "genetic uniformity" and the relevance of having separate breeding programmes for the three major areas of potato cultivation in India. Attempt has also been made to give some directions for choosing selections for use as parents and release as cultivars based on their coefficient of relationship so as to broaden the genetic base of the future potato cultivars.

Assessment of Genetic Diversity in Crop Plants - An Overview

“…Other related measure is 'Relative Genetic Contribution (RGC)' computed by partitioning the genetic constitution of a selection into theoretical percentage attributable to different ancestors [34]. The mean genetic contribution of a given ancestor is estimated by the mean of the relative genetic contributions of this ancestor to all varieties released.…”

Production and characterization of somatic hybrids between Solanum tuberosum L. and S. pinnatisectum Dun.

“…Conditions for late blight remain conducive throughout the crop season in the hills and frequently in the plains of India, which needs to be effectively managed by growing the resistant cultivars. Unfortunately, all the present-day Indian potato cultivars have very narrow genetic base those rely upon few parents having mainly the major R genes providing vertical resistance to late blight (Gopal and Oyama 2005), which are broken down with the appearance of complex races of P. infestans. A remarkable example of the Indian potato variety is Kufri Jyoti once resistant to late blight is now categorised as highly susceptible.…”

Challenges and Way-forward in Selection of Superior Parents, Crosses and Clones in Potato Breeding

“…Tuberosum crosses (Maris 1969(Maris , 1989Tarn and Tai 1983;Tai 1994); as a result new varieties have not made a major impact on yield improvement of potatoes (Van der Plank 1946;Seiffert 1957;Howard 1963a, b;Gopal 2006) in most of the countries. This is attributed to the relatively narrow genetic base of this subspecies (Mendoza and Haynes 1974a); most tuberosum varieties, then, are more or less closely related to each other (Gopal and Oyama 2005) being descended from a small number of introductions of South American potatoes (Simmonds 1962). Gp.…”