International Journal of Agricultural Policy and Research
Vol.5 (7), pp. 125-128, July 2017
Available online at https://www.journalissues.org/IJAPR/
Article 17/ID/JPR026/04/ pages
Author(s) agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License.
Original Research Article
Earliness and suppression of its additive genetic effects by environmental and management factors in cotton (Gossypium Hirsutum L.)
Scientist,Department of Genetics and Plant breeding,Cotton Research Institute of Iran (Areeo).
Author’s Email: Hooshmandh2004(at)yahoo.com
Earliness is an important breeding objective in upland cotton improvement. An experimental project for integration of earliness genes from sindose-80 to bulgare-557 with assuming that inheritance pattern of earliness characteristic in cotton cultivars controlling by additive model of genetic effects carried out during 2005 to 2016 in the Department of Botany, University of Pune and Agricultural Research Center of Tehran-Iran. With this arrangement that for single cross between the two above mentioned lines in 2005 and 2011, five years selection have been done after every crosses. Obviously the second cross in 2011 considers as back cross. In 2016 the new earliness genotype by two different planting dates compared with the five native and commercial cotton varieties in RCBD design. The criteria for earliness were (1) Early flowering days on the basis of germination to first flowering (EFD). (2) Fraction of first picking to the total seed cotton yield (FFP). (3) Earliness Bartlett’s index (EBI) and finally (4) Earliness index of combined picking and day (CPD) which has been presented as a new earliness index in this paper. Comparison of the four mentioned formulae shows the effects of weight and time in the last accurate formulae. If the earliness criteria of cotton cultivars were compared in the inappropriate condition of cotton growth, the environmental and management suppression factors like soil moisture, soil fertility level, pest pressure, temperature and cloudy weather can affect earliness criteria which are controlling by additive quantitative genes despite of dominant qualitative genes.
Key words: Earliness, additive genes, cotton, indexes