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Title:	Evaluation of some new rice variants for grain quality, nutritional value and genetic composition
Authors:	Parviz Fasahat (P46789)
Supervisor:	Sharifah Kharidah Syed Muhamad, Prof. Madya Dr.
Keywords:	Dissertations, Academic -- Malaysia Rice Agronomy Rice-Varieties Grain
Issue Date:	2-Aug-2012
Description:	Physicochemical properties of twelve new rice variants were evaluated to identify the most promising variants as new cultivars. The variants (advanced breeding lines from BC2F7) generation were derived from the interspecific cross, O. sativa L. subsp. indica cv. MR219, which is a popular high yielding Malaysian rice cultivar and O. rufipogon Griff. All ten white grain variants were collected from main season of three different agro environments [Sungai Besar (B), Gurun (G) and Seberang Perai (S)] in 2008 in Peninsular Malaysia. On the basis of head rice percentage, variants G7 and G16 showed significantly (p<0.01) higher head rice (81.6 and 80.3% respectively) across the environments. One Quantitative Trait Loci (QTL) for head rice percentage; qHR-2 was detected in G16. Filled rough rice ratio was slightly skewed towards higher values, suggesting that most of the variants had good filled rough rice counts. All variants had minimal incidence (<10%) of chalkiness and the interaction between genotype × environment did not show significant effect on chalkiness. There was a low positive correlation between the percentage of chalkiness with immature rice grain percentage (r=0.28, p<0.05). The protein content of four variants; G4 (9.1%), G16 (9.3%), G19 (9.1%) and G25 (9.2%) were not significantly different across the environments. Variants showed significant differences in amylose content within the environment and for most of the variants amylose content showed intermediate level from 20-25%. Out of 36 SSR markers tested for introgression analysis, O. rufipogon chromosomal segments were detected in 10 chromosomes by 21 markers. Two variants (G33 and G37) with red pericarp color were evaluated at a single location for containment purposes, following the same experiments. The fat content of G33 (2.3%) and G37 (2.5%) was not significantly different from MR219 (2.3%). Variants G37 and G33 had 19.7 and 18.9 percent amylose content respectively, which were significantly lower than MR219 (21.8 %) and classified as a low amylose rice. The two red pericarp variants together with the parents and a commercial red rice from Thailand were selected for measuring total antioxidant activities and vitamin E content. All variants analyzed exhibited appreciable scavenging activity against free radicals. The 2,2-diphenyl-1-picrylhydrazyl (DPPH•) scavenging varied from 83.3% (O. rufipogon) to 86% for G33 and G37. Compared to MR219, both red rice variants contained higher total phenolic content (TPC). Ferric reducing ability power (FRAP) values ranged from 69.71 to 254.29 umolFeSO4/g with lower value coming from white rice (MR219) and higher value for O. rufipogon. TPC and FRAP were positively correlated (r=0.77). The average concentration of total tocols (α-T, γ-T, αT3, γ-T3 and δ-T3) ranged from 0.06-3.17 mg/100 g rice (dry weight basis). The levels of γ-tocotrienol, the most abundant tocol found in the variants, ranged from 0.04 and 1.25 mg/100g with average of 0.69 mg/100 g, which accounted for 44% of total tocols content (9.21 mg/100 g). Semi-quantitative PCR analysis performed with homogentisic acid geranylgeranyl transferase (OsHGGT) gene specific primers showed high expression of this gene in seeds of O. rufipogon at milk and mature stages. Expression of this gene was consistent with the levels of γ-tocotrienol except for MR219 and the main reason would be translation repression.,Certification of Masters/ Doctorial Thesis" is not available
Pages:	172
Call Number:	QK495.G74F348 2012 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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