Kernel elongation after cooking is an important character of fine rice and most rice consumers prefer length-wise elongation. Although improvement of aromatic rice began early in the 1970s, until now the mechanisms and genetics of kernel elongation has remained unrevealed. Kernel elongation is considered as a physical phenomenon and is influenced by several physicochemical and genetic factors, including genotypes, aging temperature, aging time, water uptake, amylose content and gelatinization temperature. Recently the complete genetic map of fine rice has been created and the gene responsible for kernel length identified; moreover, this gene is tightly linked with the cooked kernel elongation trait. Several molecular markers linked with cooked kernel elongation have been developed. These tools will be helpful for the improvement of this important trait. For the proper study of cooked kernel elongation of rice, this review paper will provide the basis and directional materials for further studies.
In this study, we investigated the effects of 2,4-Dichlorophenoxy acetic acid (2,4-D) treatment on selected physiological parameters and fruit quality of wax apple fruits under field conditions. Foliar spray of 2,4-D at 0, 5, 10 and 20 mg L-1 concentrations were used from bud stage to the 3rd week of fruit development. Physiological parameters determined included net photosynthesis, stomatal conductivity, chlorophyll content and chlorophyll fluorescence. Net photosynthetic rate and photosynthetic efficiency via chlorophyll fluorescence significantly (p≤0.05) increased with 5 and 10 mg L-1 2, 4-D treatments. Furthermore, 5 mg L-1 2,4-D reduced bud and fruit drop, increased fruit weight and dry matter content in leaves. An improved fruit set, enhanced fruit growth, faster color development and advanced maturity were also recorded in treated plants. In addition, fruit yield increased by 39 and 48% with 5 and 10 mg L-1 2,4-D treatments, respectively. Fruit K+ content, total sugar, protein content and chalcone synthase (CHS) activities increased with 2,4-D treatments. Increased leaf soluble protein and elevated sucrose phosphate synthase (SPS) activity were also observed in 5 mg L-1 treated plants. Positive correlation between photosynthesis rate and SPS activity of leaves (R2=0.98) and between CHS activity and color development of fruits (R2=0.98) were recorded in 5 mg L-1 treatments. The results also suggested that 5 and 10 mg L-1 2,4-D treatments are promising for enhancing plant productivity and fruit quality in wax apple trees under field conditions.
Malaysian giant prawn, Macrobrachium rosenbergii (de Man, 1879), is an important crustacean aquaculture candidate globally cultured chiefly in hot climates and seasonally in temperate zones. Although the first hatchery for artificial production of the species was established in Malaysia in 1984, however, its genetic improvement program has just started recently. This study was executed as a part of this improvement project to evaluate morphometric growth related traits of four populations collected from the Western Coast of Peninsular Malaysia and their progenies. The results of the study disclosed significant differences among these populations for all traits that were considered; with Kedah population showing significant (p