Polyploidy in a Cultivar of Black Pepper (Piper nigrum L.) and its Open Pollinated Progenies

Abstract

Black pepper (Piper nigrum L., Piperaceae) is a predominantly self pollinated crop and propagated by vegetative cuttings, even though seeds are fully fertile (Dewaard and Zeven 1969, Sasikumar et al 1991). Cultivated black pepper is a diploid of polyploid origin, with 2n 4* 52 (Mathew 1958, 1973). Variability in open pollinated progenies of black pepper was reported by Ibrahim et al. (1986). However reports on distinct morphological variants in open pollinated progenies of black pepper are lacking, except the one by Ravindran and Sasikumar (1992) . They reported 18 distinct types of morphological variants in the seedling progenies of a black pepper cultivar (Collection No:1344) , and observed high amount of variation with respect to many seedling traits. The cultivar is characterized by unusually bold berries, loose spike, late maturity, large leaves and robust stem,. A population of progenies of this cultivar raised from the open pollinated seeds is found to show variations is morphology and growth which is not frequent in the open pollinated progenies of the other cultivars of black pepper, being a predominantly self pollinated crop. In some of the progenies the initial variation sustained with growth, for leaf size and shape. Leaf thickness, leaf tip, margin and leaf base, length of petiole and internodes, stem thickness, colour of petiole shoot tip and stem, besides variation in growth rate and vigour. A few of the variant progenies resembled wild species of Piper.