Comparative performance and basis for differences among sorghum (Sorghum bicolor L. Moench) hybrids from differenct periods of sorghum improvement.
| Main Author: | |
|---|---|
| Other Authors: | , , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1983.
|
| Subjects: | |
| Online Access: | Link to ProQuest Copy Link to OAKTrust copy |
| Abstract: | Performance tests, growth analysis, as well as evaluations of combining ability and heterosis were carried out during 1981 and 1982 seasons to determine morphological, physiological, genetic and adaptational differences between old and new sorghum (Sorghum bicolor L. Moench) hybrids representing different periods of sorghum improvement. Hybrids used were ATx378 x RTx7000, ATx399 x RTx7078, and ATx3197 x RTx7078 designated as old, and new hybrids comprised of ATx623 x RTx430, ATx623 x 77CS256, and ATx2752 x RTx430. ATx623 x RTx7000 and ATx378 x RTx430 were classified as new/old and had a combination of an old and a new parent. Results indicated a 9.5 to 67.7% yield advantage for new hybrids with a mean of 32% which translated to 1500 kg/ha. New hybrids performed relatively better in dry land environments compared to old hybrids. Yield increase was manifest mainly through greater number of kernels per panicle and per unit area. Increased plant weight, leaf area, plant height, and days to anthesis in new hybrids were evident, while there were no significant differences in either kernel weights, harvest indices or threshing percentages between new and old hybrids. In general, the response of new/old hybrids was either similar to new hybrids or was intermediate between the old and new hybrids. New and old parents showed no difference for most traits studied, yet there was an indication that new parents in ideal combinations conferred stability to their hybrids. New hybrids and higher crop growth rates but were not significantly different in relative growth rates from other hybrid groups. No consistent differences in net assimilation rates between old and new hybrids were evident. Data from combining ability study pointed out the consistency of new parents in transmitting positive general combining ability (GCA) effects. 77CS256 and RTx430 had large and positive GCA effects for yield while 77CS256 had positive GCA effect for kernel number as well.... |
|---|---|
| Item Description: | "Major subject: Plant Breeding." Typescript (photocopy). Vita. |
| Bibliography: | Includes bibliographical references (leaves 90-96). |