W. M. Thagana
School of Agriculture and Enterprise Development, Kenyatta University,Kenya.
Title: Determination of haploid induction rates for tropicalized adapted inducer lines of maize
Biography
Biography: W. M. Thagana
Abstract
Conventionally, inbred lines are developed by inbreeding methods such as self-pollination, sib-mating and parent-offspring mating which take 6-8 generations. In vivo doubled haploid technology that uses haploid inducers is an efficient approach for developing completely homozygous lines in 2-3 cropping seasons. However, for production of homozygous lines on a commercial scale, haploid inducers with high haploid inducer rates is paramount. A study whose objective was to identify Haploid inducers with a high Haploid Induction Rates (HIR) was carried out in Kenya in collaboration with the International Maize and Wheat Improvement Center (CIMMYT) and Kenyatta University. A split plot arrangement in Randomized complete block design (RCBD) was used in the trial in which seven inducer lines were the main plot while three female populations were the sub plots. The seven inducer lines comprised of five first generation Tropicalised Adapted Inducer Lines (TAILs) from University of Hohenheim (TAILs 7, 8, 9, Hybrid 9*7 and 9*8) and two second generation TAILs (008 and 009) from CIMMYT. Three female populations (ligule less tester, normal population 1 and 2) were crossed with the seven TAILs. The F1s were germinated and the seedlings used to determine HIR of the TAILs using their morphological plant characters. ANOVA and correlation analyses was done using R software version 3.2.3 and means separated using the least significance difference (LSD) at α = 0.05. The second generation TAILs (008 and 009) were not evaluated for HIR since they took more days to anthesis (54) compared with silking days of female which was 49 days leading to poor seed set in the cobs. The ligule less tester and normal population 2 had the highest HIR of 7.62% and 8.49% respectively; hence they can be used for determination of HIR of target haploid inducer lines. TAILs 8 (8.48%) and 9 (7.77%) had the highest HIR hence they can be used for haploid induction in target germplasm. Plant height, anthesis days and HIR had a positive correlation for the ligule less tester. Correlation between HIR and pollen viability was positive in the morning for normal population 1 and negative for normal population 2 in the afternoon. The study was fundamental in identifying haploid inducer lines and female populations with high HIR that will be used for commercial development of homozygous lines for maize breeders in the region.