No abstract

A comprehensive knowledge on reproductive traits is a prerequisite in utilizing the existing tea germplasm effectively for crop improvement to develop superior planting material for grower acceptance and market profitability. The Sri Lankan tea germplasm was characterized based on reproductive traits viz. floral morphology, pollen biology, stigma receptivity and phenology of flowering and fruit set. The variability in floral morphology, especially the style morphological features, formed phenotypic clines rather than distinct groups. Studies on pollen biology and stigma receptivity revealed significant variability and asynchrony that could result unequal reproductive success among the genotypes. Four distinct patterns were predictable among the genotypes based on flower and fruit abundance and the time of flowering and fruit set.

Flavonol glycosides in tea leaves have been quantified as aglycones, quercetin, myricetin, and kaempferol. Occurrence of the said compounds was reported in fruits and vegetable for a long time in association with the antioxidant potential. However, data on flavonols in tea were scanty and, hence, this study aims to envisage the flavonol content in a representative pool of accessions present in the Sri Lankan tea germplasm. Significant amounts of myricetin, quercetin, and kaempferol have been detected in the beverage type tea accessions of the Sri Lankan tea germplasm. This study also revealed that tea is a good source of flavonol glycosides. The Camellia sinensis var. sinensis showed higher content of myricetin, quercetin, and total flavonols than var. assamica and ssp. lasiocalyx. Therefore flavonols and their glycosides can potentially be used in chemotaxonomic studies of tea germplasm. The nonbeverage type cultivars, especially Camellia rosaflora and Camellia japonica Red along with the exotic accessions resembling China type, could be useful in future germplasm studies because they are rich sources of flavonols, namely, quercetin and kaempferol, which are potent antioxidants. The flavonol profiles can be effectively used in choosing parents in tea breeding programmes to generate progenies with a wide range of flavonol glycosides.

No abstract

This study investigated the amino acid composition of eight local and three imported rice varieties frequently consumed by consumers in the capital of Sri Lanka. Investigation included twenty free amino acids (FAAs) analysed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and sixteen protein bound amino acids analysed using high performance liquid chromatography with diode array detection (HPLC-DAD). The mean total amino acid (TAA) in rice ranged between 64.5 ± 1.9 g/kg and 96.0 ± 5.1 g/kg on dry basis (db). Ponni, Basmathi, Rathu Nadu and Fragrant rice which were parboiled varieties, reported the overall highest mean TAA contents while imported Ponni and Basmathi exhibited the highest mean essential amino acid (EAA) contents depicting high quality protein. Red rice varieties of Nadu, Kekulu and Kekulu Samba reported signifi cantly (p < 0.05) higher mean TAA contents than their white counterpart varieties. The parboiled varieties; Rathu Nadu, Sudu Nadu, Keeri Samba and Samba reported the overall highest gamma amino butyric acid (GABA) contents (0.9 ± 0.3-5.0 ± 1.7 mg/100g). Completely polished Sudu Kekulu reported the overall lowest mean TAA, EAA and GABA contents. Except for unanalysed tryptophan, fi ndings revealed that disregarding the nutritional loss encountered during cooking irrespective of variety, consumption of approximately 100 g of raw rice (after cooking) three times a day will provide an average adult (of 50 kg body weight) more than 50 % of the daily intake of essential individual amino acids recommended by the Food and Agricultural Organization (FAO).