Morphological changes in an inbred line of pearl millet selected for downy mildew resistance uri icon

abstract

  • Downy mildew (Sclerospora graminicola) resistant Pennisetum glaucum (P. americanum) line 81B was developed by ?-irradiation of seeds of the highly susceptible line Tift 23d2B. A comparative study of the B-lines and their A-line (cytoplasmically male sterile) counterparts at Tifton (Georgia) and Patancheru (India) revealed significant differences between 81 and Tift 23d2 for 10 of the 14 common morphological characters evaluated. For days to 50% flowering and inflorescence length, differences between the 2 inbreds were in a similar direction at both locations, but for plant height and seed set differences at the 2 locations were inverse, and for number of internodes, leaf sheath length, peduncle length, number of effective tillers per plant, inflorescence diameter and seed mass, differences were significant either only at Tifton or only at Patancheru. There was also a significant difference between the 2 inbreds for internode length pattern. Thus, substantial morphological changes other than downy mildew resistance occurred in inbred 81 which could be due either to pleiotropic effects of the downy mildew resistance genes or to genetic changes at other loci. Introgression from resistant breeding material leading to concomitant changes in downy mildew resistance and morphological characteristics is also possible

publication date

  • 1990