A comparative analysis of biparental mating and selfing in pearl millet (Pennisetum typho�des) S & H

Abstract

A study was made of the nature of variation and changes in association for characters related to yield, development and disease resistance in two sets of progenies one set derived through biparental mating (A-series) and the other by traditional inbreeding (selfing) from the F2 onwards (T-series), in a 22 × 22 diallel of dwarf derivatives of Pennisetum typhoides S & H. Comparison of means and variances within and between the two groups of progenies (A and T-series) and with those of released hybrids (HB-1, HB-2, HB-3, HB-4) for seventeen characters (six related to development, six to productivity, three to vegetative growth and one each to earliness and disease incidence) showed significant variation among the lines of the two series for synchrony of tillering, earliness, disease incidence, chlorophyll depth, grain hairiness, tiller number, plant height, length of earhead, grain yield and grain weight. The A-series selections were significantly superior to the T-series for most of the characters, indicating the effectiveness of selection in biparental matings compared with selection in selfed progenies for these traits. Many of the A-series (220 out of 800) selections were also superior to the existing released hybrids.Changes in the magnitude and nature of association among twelve important characters in the two populations were more favourable in the biparental matings: of 66 possible correlation coefficients examined, 25 cases were found with changes in favour of selections from biparental matings (A-series). These changes were probably due to the breakage of unfavourable linkages and changes in phase of linkage, and indicate the usefulness of biparental matings in the simultaneous improvement of the population for several attributes.

Comparative Study on Impact of Mating Systems on Character Associations in Single Crosses of Maize (Zea mays L.)

“…While pleiotropic effect cannot be manipulated, association due to linkage can be affected by deploying appropriate breeding programmes. In a study, biparental mated progenies of pearl millet exhibited additional twelve favourable associations than selfs [7]. The negative or nonsignificant correlations observed in open pollination indicate that these populations are in linkage disequilibrium and any linkage observed may be due to prevalence of repulsion type linkage.…”

Γενετική ανάλυση ποσοτικών χαρακτηριστικών στην πεπονιά (Cucumis melo L.)

“…1978). Αναμφίβολη ένδειξη αυτής της φύσης σε μεγάλους πληθυσμούς παρατηρήθηκε στο αγροστωδες φυτό Κεχρί για πολλά χαρακτηριστικά, με μια συγκριτική ανάλυση των διγονικών διασταυρώσεων και των αυτογονιμοποιήσεων, (Singh and Murty, 1973).…”