Quantitative genetic analysis and rice kernel elongation improvement in MR219 × Mahsuri Mutan and MR219 × Basmati 370 populations
In Malaysia, there is increasing demand for specialty rice especially in preparing dishes such as Nasi Arab and Biryani. High kernel elongation (HKE) is one of the high-quality characteristics in rice. However, limited studies in Malaysia were done on quantitative genetics analysis of high kernel...
Saved in:
| Main Author: | |
|---|---|
| Format: | Thesis |
| Language: | English |
| Published: |
2019
|
| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/90116/1/FP%202019%2071%20ir.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | In Malaysia, there is increasing demand for specialty rice especially in
preparing dishes such as Nasi Arab and Biryani. High kernel elongation (HKE)
is one of the high-quality characteristics in rice. However, limited studies in
Malaysia were done on quantitative genetics analysis of high kernel elongation
that contribute to this important trait. Rice varieties such as Mahsuri Mutan and
Basmati are categorized as specialty rice with kernel elongation ratio
exceeding 1.6 and 2.0, respectively. The main objective of this study was to
determine the genetic control and inheritance patterns of high kernel
elongation of and related physico-chemical characteristics in several
generations of Mahsuri Mutan and Basmati 370 crossed with MR219, also to
study the ageing effect on structure of milled and cooked rice of traditional
variety Mahsuri and modified variety, Mahsuri Mutan. Generation means
analysis and scaling tests were carried out to estimate additive- dominance
genes model. From this study, Mahsuri Mutan and Basmati 370 showed
superior high kernel elongation as compared to their respective progenies.
The F1 generation for both populations had intermediate HKE which were 1.65
and 1.66 for Mahsuri Mutan and Basmati 370 based populations. This study
also found that ageing treatment directly affected the increasing HKE for both
populations. In both populations, most of the characters including HKE were
controlled by additive and dominant gene actions suggesting that selection for
HKE could be done from one generation to another using recurrent selection
method. Presence of epistasis for both populations where MR219 × Mahsuri
Mutan showed complimentary epistasis and MR219 × Basmati 370 showed
duplicate epistasis. This also shows that the HKE trait was controlled by nonallelic
interaction. Estimated heritability values of HKE for both populations
were moderate (54% for Mahsuri Mutan and 63% for Basmati 370). The
inheritance patterns of F2 generations showed goodness of fit with the Mendelian ratio of 3:1 (normal kernel elongation ratio: high kernel elongation
ratio). Phenotypic path coefficient analysis showed that CGL, PC, and LW
traits had direct and indirect contribution to HKE trait. Phenotypic correlation
coefficient indicated that there was a high positive correlation between HKE
and water uptake ratio. The ageing treatment also showed significant
difference for all the physico-chemical traits for all parental lines. Observation
under SEM for milled and cooked of samples Mahsuri and Mahsuri Mutan
showed that the ageing samples had more cracks on the tissue structure
compared to normal rice samples. Moreover, the shape of the tissue structure
also give effect on kernel elongation, for example, the hexagon structure in
Mahsuri Mutan gave more elongation effect on kernel. The findings from this
study on HKE of Mahsuri Mutan and Basmati 370 could be useful to breeders
in selection and development of new specialty rice variety. |
|---|