Distribution of red rot resistance in progenies of sugarcane varietal crosses and its relation with sugar content.

摘要

The inheritance of resistance to red rot (caused by Colletotrichum falcatum [Glomerella tucumanensis]) was investigated in progenies of 6 sugarcane crosses in Motipur, Bihar, India. When both the resistance (R) parents were involved, the progenies were more towards resistance. The cross Co932 x BO91 (RXR) produced the maximum (45.2%) resistance progenies followed by CoSe 92423 x Co 62198 (32.6%). When only one of the parents involved was resistant CoS 90269 (R) x CoS 510 (S), CoSe 92423 (R) x CoS510 (S) and CoS 88216 (S) x Co87272 (R) or both parents were susceptible Co 1158 x CoJ 46 less resistance types were produced. Disease resistance was also studied in relation to sugar content (H.R. Brix). Approximately 38-78.9% progenies had low sugar content (up to 17% H.R. Brix) and 21.2-47% progenies were under medium sucrose level (17.1-19.0% HR Brix). However, 9.5-16.6% offspring had high sucrose level (19.1-21.0 H.R. Brix). Very few progenies (2.8-4.8%) had very high H.R. Brix (above 21.0%). Some 23.9% progenies of 6 crosses were found resistant at low to medium H.R. Brix level. However, at high to very high H.R. Brix level, progenies were also found resistant. H.R. Brix value, an indicator for high quality, is not associated with the resistance.