Inheritance of induction radiation sensitivity of space flight environments and γ-radiation on rice
Abstract
There are many factors affecting living things during space flight, such as microgravity, cosmic radiation, etc. A large number of plant mutants have been obtained after space flight on satellite in China in the last decade and some commercial crop varieties were released. However, little consideration has so far been given to the genetic mechanisms underlying sensitivity of plant seeds to space flight environments. To reveal the genetic mechanisms associated with induction radiation sensitivity (IRS), a set of 226 recombination inbred lines (RILs) derived from Lemont (japonica)/ Teqing (indica) F13, were analyzed using 164 well-distributed DNA markers and assayed for the traits related to IRS including rate of survival seedling (RSS), seedling height (SH), seed setting rate (SSR) and total physiological damage (TPD) in replicated trials after space flight on Chinese Shenzhou IV Spacecraft andγ -radiation treatment (35000 rad) on the ground in 2002. Seedling growth of Lemont was accelerated after space flight with the SH of 116.2% of ground control while growth suppression was happened for Teqing with the SH of 85.7% of ground control. γ -radiation treatment resulted in significant decrease in all tested traits for the two parents, indicating space flight and γ -radiation treatment had different biological effects on the two parents. Significant differences were detected among the RILs for their responses to space flight environments and γ -radiation, reflected as the difference in the four tested traits. Space flight resulted in stimulation on growth for 57.1% lines whileγ -radiation had suppression on growth for most lines. Seventeen putative main-effect QTLs was identified for the four traits related to IRS under space flight and γ -radiation, which totally explained significant portions of the total trait variation (4.4% for RSS, 27.2% for SH, 4% for SSR and 15.8% for TPD for space flight; 10.4% for RSS, 15.1% for SH, 8.2% for SSR and 6.1% for TPD forγ -radiation). Same QTLs affecting some of the four tested traits after space flight andγ -radiation treatment were identified, suggesting that space flight environments andγ -radiation partially shared the same genetic mechanisms for mutation. Forty-nine epistatic pairs affecting the four traits was detected and totally explained significant portions of the phenotypic variation (49.7% for RSS, 49.8% for SH, 14.3% for SSR and 40.2% for TPD for space flight; 30.5% for RSS, 18.1% for SH, 34.3% for SSR, 31.9% for TPD forγ -radiation). It indicated that IRS is a very complicated trait and epistasis may play an important role in underlying its genetic mechanism. Based on these results, the genetic basis of IRS and its application in plant mutation breeding was discussed.
- Publication:
-
35th COSPAR Scientific Assembly
- Pub Date:
- 2004
- Bibcode:
- 2004cosp...35.1117X