Registration of ICMA 841 and ICMB 841 Pearl Millet Parental Lines with A1 Cytoplasmic‐Genic Male Sterility System

Abstract

One pair of A (male sterile) and B (maintainer) lines of Pennisetum glaucum [P. americanum] with the A1 cytoplasmic-genic male sterility system was made available in 1987 as seed parents for the production of hybrids throughout India. The lines are designated ICMA841 and ICMB841 (PI537587); they were previously tested as 841A and 841B. Both are highly resistant to downy mildew (Sclerospora graminicola). The A line, being medium in height, gives medium to tall hybrids, depending on the height of the pollinator. ICMA841 and ICMB841 were developed from 514A and 514B, which later succumbed to downy mildew in India. The original 514A and 514B stocks showed genetic variability for several traits, including resistance to downy mildew when planted in the downy mildew screening nursery at the ICRISAT Centre. Vigorous, downy mildew-free 514B plants were selfed and crossed to downy mildew-free plants of 514A. This process of selection, selfing and backcrossing was repeated twice a year in the downy-mildew nursery, using pedigree selection for 4 generations. ICMA841 and ICMB841 were chosen on the basis of phenotypic similarity, vigour, tillering, seed set and freedom from downy mildew. ICMA841 and ICMB841 are moderately tall (140-180 cm), moderately tillering (2-5 tillers/plant) and lodging resistant and show medium maturity (53-58 days to 50% flowering). Panicles are of medium length (16-21 cm), compact and generally cylindrical to conical. The 1000-grain weight is 6-8 g. Test hybrids made with ICMA841 matured 4 to 6 days later than those made with 514A and are 15 to 20 cm taller. In addition, ICMA841 and the hybrids derived from it remained green after seed maturity thus allowing the stover to be used as green fodder at harvest.