Morphological, physiological and molecular analysis of Line × Tester in Populus deltoides Bartr

Abstract

In the present investigation, male and female clones/strains/species of Populus deltoides procured from State Forest Department, Haldwani and Shyampur, Haridwar Forest Division and maintained in the germplasm block of Naganji nursery from which 11 male and 13 female clones were included in the reproductive study and the selected plant material of 4 females (G-48, S 1, S 7 C 8 and L-62/84) and 4 males (S 7 C 11, L-17/92, L-124/86 and S 7 C 1) clones were crossed using Line × Tester (4 × 4) mating design. Control crossing was done and seedlings were raised in the nursery at stage-1 and were evaluated for morphological characters. In stage-2 clonal cuttings of selected individuals were raised in RBD and were evaluated for morphological, physiological and wood characters. The gene action study revealed that dominance variance was observed more than the additive variance for all the parameters studied. The proportional contribution of lines was higher than individual contribution of testers or line × tester interaction except for plant height, collar diameter, internodal length, leaf area, maximum width of leaf, angle between the mid rib and 2 nd lower lateral mid rib, shoot bark thickness, root bark thickness, fresh shoot weight, dry shoot weight, dry root weight, dry root shoot ratio, root length, total fresh weight, total dry weight, stomatal conductance and fibre length. Among 18 SSR markers, fifteen markers showed monomorphic allelic pattern, the remaining three markers (PMGC-2060, PMGC-2020 and PMGC-451) showed polymorphic pattern. A close appraisal of the SSR banding pattern obtained after the amplification of genomic DNA of both the parents and their hybrids revealed that, all the hybrids were similar to their parents.