Palynological approach to screen coconut genotypes for high temperature tolerance
| dc.contributor.advisor | Hebbar, K B | |
| dc.contributor.author | Anusree, R Nair | |
| dc.contributor.author | KAU | |
| dc.date.accessioned | 2020-03-04T08:21:38Z | |
| dc.date.available | 2020-03-04T08:21:38Z | |
| dc.date.issued | 2017 | |
| dc.description | PG | en_US |
| dc.description.abstract | Climate change is expected to rise the global atmospheric temperature at a rate of 0.2°C per decade. Temperature is one of the most important factors which drives the growth and development of the crops. Reproductive phase of the crop is more sensitive to high temperature than vegetative phase. In that pollen germination and pollen tube length are known to be more critical thereby effecting fruit set and yield. In this study coconut genotypes (12 numbers) were screened using the in-vitro pollen germination technique at 10 to 50 °C at an interval of 2.5 °C and the tolerance of the selected genotypes was confirmed invivo pollination during two extreme conditions of winter and summer. Maximum pollen germination (54.3%) and pollen tube length (554.5μm) was observed at 25 °C and either increase or decrease in temperature decreased the germination. Temperatures above 40 °C and below 15 °C germination became nil in most of the genotypes. The mean cardinal temperatures (Tmin, Topt, and Tmax) averaged over genotypes, were 12.8 °C, 26.53 °C and 43 °C for pollen germination and 12.7 °C, 27.53 °C and 42.96°C for pollen tube growth.Talls WCT, LCT, FMST, dwarfs COD,GBGD and hybrids showed better adaptability to high temperature. Dwarf variety MYD on the other hand was highly sensitive. If dwarf variety COD had high germination at low temperature another dwarf GBGD showed high germination under high temperature suggesting differential response amongst genotypes. As we had hypothesized nut set was better during winter and above 30 °C it was reduced under field condition. Nut set was low with invivo pollination by the pollens from temperature sensitive variety CGD compared to the pollens used from tolerant varity COD and WCT. Biochemical constituents like sugar and amino acids and enzyme activity were found to be affected under high or low temperature. From the study it is clear that the genotypes screened invitro for pollen germination can be used in breeding programs to develop new genotypes that can withstand high temperature conditions both in the present climate as well as in future warmer climate. | en_US |
| dc.identifier.uri | http://krishikosh.egranth.ac.in/handle/1/5810144190 | |
| dc.keywords | Climate change, Pollen viability, Coconut, Cocos nucifera, Inflorescence, In vitro pollen germination, Amino acid, Sucrose | en_US |
| dc.language.iso | en | en_US |
| dc.pages | 143 | en_US |
| dc.publisher | Academy of Climate Change Education and Research Vellanikkara | en_US |
| dc.sub | Climate Change Adaptation | en_US |
| dc.subject | null | en_US |
| dc.theme | Palynological approach to screen coconut genotypes | en_US |
| dc.these.type | M.Sc | en_US |
| dc.title | Palynological approach to screen coconut genotypes for high temperature tolerance | en_US |
| dc.type | Thesis | en_US |