A novel method for simultaneously estimating yield parameters and disease incidence for neck blast using half-plant panicles inoculation approach in rice (Oryza sativa L.)

Abstract

A new procedure is described to screen neck blast disease and simultaneously evaluate for grain yield within the same plant and estimate yield losses if any. Taking the example for neck blast resistance, fourteen rice (Oryza sativa L.) genotypes were evaluated for neck blast using the "half-plant panicles inoculation approach" to check the possibility of simultaneous screening for both yield parameters and neck blast resistance, thus avoiding loosing the valuable genetic material. In this approach half the number of panicles in each of the five selected plants of each genotype were inoculated with mixed blast isolates and the other half of the panicles of a plants were used as uninoculated control. The results from this approach were then compared with two other treatments where in all the panicles in the selected five plants were inoculated with the mixed isolate spores and untreated as control plants, respectively. The results indicated that no significant difference in the yield loss between the whole plant inoculated and whole plant uninoculated control and yield loss between the inoculated and uninoculated panicles of the same plant (half the number of panicles inoculated and rest was untreated control). This approach serves as a valuable method to simultaneously estimate yield parameters as well as neck blast incidence within the same plant and, thus helps to avoid having several treatments and progeny testing in segregating generations.