Exploratory Environmental Science Research
Volume 2 – Issue 1 – 2021
Original Research Article
The Analyses Of Mapping Tightly Linked Markers Of A Single Dominant Heat-Tolerance Gene In Indica Variety, TCS17
Ching-Chu Yen1,2
1Yun-Lin County Dounan Senior High School, (TAIWAN)
2No.212, Zhongshan Rd., Dounan Township, Yunlin County 63044, (TAIWAN)
PAGE NO: 87-94
ABSTRACT – DOI: https://dx.doi.org/10.47204/EESR.2.1.2021.087-094
In the past three decades, global warming has led to an increase in annual average temperature. This high temperature stress is a serious threat to the growth and yield in rice. Therefore, scientists study hard to find heat-tolerance genes and breed heat-tolerance rice lines. Ten years ago, a 100%-explaintion heat-tolerance gene was discovered in my salt-tolerance research on screening, inheritance and linkage marker analyses of salt tolerance in mutated scented japonica rice, to develop elite salt-tolerant varieties suitable for salinized areas[24,25]. In view of this, I began the first analysis of mapping tightly linked markers of a single dominant heat-tolerance gene in indica variety, TCS17, explaining 100% of the phenotypic variation. I reported the results of this heat-tolerance gene analysis, hoping to help scientists to find salt-tolerant genes and cultivate salt-tolerant strains. The analyses can solve the problem of high temperature stress in rice and help humans deal with future food shortages.
Yen (2011) and Yen and Lin (2011) treated the seedlings of 1005 mutated scented japonica rice lines with six true leaves with 300 mM NaCl for three days. Only the salt-tolerant line, SM61, survived. We obtained F2 populations from the cross between a salt-tolerant and heat-susceptible japonica line, SM61, and a salt-susceptible and heat-tolerant indica variety, TCS17. After culture with 35/25°C (day/night) and 200 mM NaCl for five days, the heat-tolerant and salt-tolerant surviving (R) to heat-sensitive or salt-sensitive non-surviving (S) ratio in 290 F2 plants showed a good fit to the Mendelian 3 : 13 segregation ratio by a Chi-square test indicating that the heat-tolerance of TCS17 was governed by a single dominant gene. The heat-tolerance gene explained close to 100% of the total phenotypic variation, and was tightly linked to C61009 (marker) located on chromosome 4. This is the first report of mapping tightly linked markers of a single dominant heat-tolerance gene. These linkage markers can efficiently provide the fine mapping, cloning and sequence comparison, as well as the functions of the new heat-tolerance gene, answering the question of how the gene controls heat tolerance.