Samaru Journal Of Agricultural Education
Volume No: 7|
ISSN: 0794 – 7860|
Page No: 90
| FullText PDF
Title: INHERITANCE PATTERNS OF THE OKRA –LEAF TRAIT AND RESISTANCE RATING TO LEAF ROLLING IN COTTON UNDER THREE DIFFERENT CONDITIONS
YAHAYA, A.I., ADO, S.G., ISHIYAKU, M.F., ONU, I., MOHAMMED, M.S., BUGAJE, S.M., AND USMAN, A.
INSTITUTE FOR AGRICULTURAL RESEARCH (IAR), AHMADU BELLO UNIVERSITY SAMARU ZARIA- NIGERIA&NBSP;
Resistant plants retard the growth and rate of reproduction of insect pests that cause leaf rolling. The objective of this study was to get information on the pattern of inheritance for okra-leaf trait in cotton and to evaluate its effects on leaf rolling under three different conditions. Entry CL07, an okra leaf cotton introduced from Egypt (highly resistant to leaf rollers), was crossed to two commercial varieties, SAMCOT 10 and SAMCOT 12. The resulting F1s and their parents were advanced. F2s and backcross generations patterns estimated using the F2 data and the backcross populations. Chi-square test was employed to test for the goodness of fit of the data observed on an expected segregating phenotypic ratios of the F2 (1:2:1) and backcross generations (1:1) in the two crosses, under three environments: pesticide sprayed, unsprayed and screen house conditions. The result showed equal number of okra and normal leaf types in cross II (SAMCOT 12 x CL07) in the sprayed condition of cross I (SAMCOT 10 x CL07) and in both crosses under screen house conditions. Segregation for leaf shape fitted into the ratio of 1 okra: 2 sub-okra:1 normal, which confirmed incomplete dominance in the inheritance of leaf shape. In the screen house condition, infestation ranged from 0-31% while in the screen house condition it ranged from 10-36%. Parent one (P1) and backcross one (BC1) were resistant to leaf rollers irrespective of crosses (Cross I and II) and conditions. Non application of pesticide enhanced leaf roller infestation by 14-15 %.It was concluded that the cotton genotype CL07, clearly demonstrated host plant resistance to the cotton leafroller, Sylepta derogata. Host plant resistance through incorporation of okra leaf trait could provide an effective management of leaf roller in cotton.