Recurrent Restricted Phenotypic Selection Increases Forage Yields of Pensacola Bahiagrass1

Abstract

Recurrent restricted phenotypic selection (RRPS), modified form of mass selection, was evaluated as a breeding technique for improving the forage yield of Pensacola bahiagrass (Paspalum notatum var. saure ‘Parodi’), a sexual diploid. Selection was based on single green weights of spaced plants at the end of the first season and spring yield the following year. Four cycles of RRPS increased forage yield of this grass 17.7% over that of the commercial check. The rate of progress per 2‐year cycle in a previously selected narrow‐gene population (NGP) was about 2%/cycle. In an unselected wide‐gene population (WGP), rate of progress was 6%/cycle. Variances and coefficients of variability (CV's) for yield spaced plants of the original and fourth‐cycle populations compared in the same test were similar for the NGP but were reduced substantially to the NGP level in the WGP. RRPS increased the frequency and yield of high‐yielding plants. Increasing seeding rates from 3 to 27 kg/ha in methyl bromide treated soil increased firstyear forage yields 76%, but had no effect on the relative yields of the commercial check and the fourth‐cycle populations. The data suggest that rate of progress could be doubled by use of a 1‐year cycle and the saving of 3 to 4 rather than 5 of the best plants in each 25‐plant block.