Genetic divergence in trifoliate citrus rootsctocks under sub-tropical conditions of Punjab

Abstract

The present investigation was aimed to assess genetic diversity in citrus trifoliate rootstocks. The research work was carried out on five citrus trifoliate (Poncirus trifoliate and its hybrids) rootstocks. Their evaluation was done for characters as per IPGRI citrus descriptor. Most of the quantitative trees, leaves, flowers and fruit characters were found statistically significant. Leaf lamina length was recorded maximum in strain Flying Dragon (54.4 mm) which was at par with Rich 16-6 and X-639 and minimum in Gonicoppal Trifoliate (32.4 mm). The leaf lamina width was maximum for Trifoliate (22.1 mm) and was found minimum for Gonicoppal Trifoliate (15.7 mm). The average leaf chlorophyll content ranged from 50.7 in Flying Dragon strain of trifoliate to 65.5 in Trifoliate. The strains were differed with respect to full bloom.The total soluble solids was recorded maximum in strain Flying Dragon (12.1 oBrix), which was at par with Rich 16-6, and the lowest was recorded in strain Trifoliate (8.8 oBrix). Highest acidity was recorded to be 3.5 per cent in X-639, Rich 16-6 and Trifoliate while the lowest was recorded for Flying Dragon (1.3 %). The mean number of seeds per fruit was highest in Rich 16-6 (26.0) and the lowest was found in X-639 (7.0), which was at par with Flying Dragon. The strains also differed significantly for seed length and breadth.The study concluded a significant genetic variance in strains under investigation.