Genotype by Environment (G x E) Modeling of the Variable Initiation of Parthenocarpy sensu stricto in Musa: Elucidation of the Environmental Components of Variable Expressivity of Parthenocarpy in a Facultative Apomictic Musa acuminata Subspecies Microcar
A. A. Shaibu *
International Institute of Tropical Agriculture (IITA), Nigeria and IITA High Rainfall Station, Onne, Nigeria, IITA Headquarters Central Biotechnology Laboratory, Ibadan, Nigeria and IITA Humid Forest Ecoregional Center, Yaounde, Cameroon and Department of Crop, Soil Science and Forestry, Rivers State University of Science Technology, Port Harcourt, Nigeria
P. Okoro
IITA High Rainfall Station, Onne, Nigeria, IITA Headquarters Central Biotechnology Laboratory, Ibadan, Nigeria. IITA Humid Forest Ecoregional Center, Yaounde, Cameroon. Department of Crop, Soil Science and Forestry, Rivers State University of Science Technology, Port Harcourt, Nigeria
G. Ude
International Institute of Tropical Agriculture (IITA), Nigeria
B. A. Olukolu
International Institute of Tropical Agriculture (IITA), Nigeria
I. Ingelbrecht
International Institute of Tropical Agriculture (IITA), Nigeria
A. Tenkouano
IITA High Rainfall Station, Onne, Nigeria, IITA Headquarters Central Biotechnology Laboratory, Ibadan, Nigeria and IITA Humid Forest Ecoregional Center, Yaounde, Cameroon
M. N. Ogburia
Department of Crop, Soil Science and Forestry, Rivers State University of Science Technology, Port Harcourt, Nigeria
F. Moonan
International Institute of Tropical Agriculture (IITA), Nigeria and IITA High Rainfall Station, Onne, Nigeria, IITA Headquarters Central Biotechnology Laboratory, Ibadan, Nigeria
C. Dimkpa
Utah State University of Biological Engineering, 4105O old Main Hill Logan UT, 84322-4105 U.S.A
*Author to whom correspondence should be addressed.
Abstract
To better understand the genome by environment (G x E) interactions that need to be accommodated in order to better predict hybrid performance for a high breeding value vegetative parthenocarpy trait sensu stricto. An analysis of the possible environmental signals contributing to the variability of a vegetative parthenocarpy trait sensu stricto via the genome x environment initiation of a genetic lesion that temporally, developmentally and systematically results in abortion of a parthenocarpic developmental regime was performed utilizing Musa acuminata accession Borneo as a model plant. We examined the effect of the variable and potentially modulating environmental signals, and performed a dissection of the genetic components of expressivity and penetrance in the vegetative parthenocarpy in Borneo, utilizing 180 apomictic progeny planted at different developmental ages in duplicate at each of two ecoregional zones. A total of 2,160 floral rachis from 720 mats of Borneo were measured for their subsequent expressivity and penetrance for vegetative parthenocarpy across individual flowers produced from a single vegetative mat, across local duplicate mats, and across ecoregional zones. The results of our study have produced a predictive G x E Model for expressivity of vegetative parthenocarpy in Musa, with validation of this model by a variety of statistical and probabilistic methods. Since expressivity of vegetative parthenocarpy to similar environmental signals have been identified across the monocot to dicot plants such as tomato, the generalized use of models such as presented in our study may have broader applicability to a wider range of crop plants
Keywords: Expressivity, genotype x environment, model, parthenocarpy, penetrance