A quick DNA extraction protocol: Without liquid nitrogen in ambient temperature

Marker assisted selection is an effective technique for quality traits selection in breeding program which are impossible by visual observation. Marker assisted selection in early generation requires rapid DNA extraction protocol for large number of samples in a low cost approach. A rapid and inexpensive DNA extraction protocol has been described for different tissues of color rice and other plant species which contain pigment and polyphenolic compound. This method has been modified from well known cetyltrimethylammonium bromide (CTAB) method where CTAB is used for DNA extraction. This protocol is simple and fast compared to other methods and no liquid nitrogen is required. Only inexpensive chemicals and ordinary laboratory equipments are enough for DNA extraction. The quantity of total genomic DNA from different tissues was almost similar which was extracted from 10 mg samples. The extracted DNA is stable and applicable to marker assisted selection, DNA fingerprinting, quantitative traits loci analysis, screening of transformants and enzymatic digestion.Key words: Different plant tissues, inexpensive, rice flour, rapid DNA extraction

Physiology of seed yield in soybean: Growth and dry matter production

A field study was conducted to assess the growth parameters controlling the dry matter and seed yield of soybean. The result shows that growth rate was slow during vegetative phase in all genotypes. A relatively smaller portion of total dry mass (TDM) was produced before flower initiation and the bulk of it after anthesis. Maximum absolute growth rate (AGR) was observed during pod filling stage in all genotypes due to maximum leaf area (LA) development and leaf area index (LAI) at this stage. Plant characters like LAI and AGR contributed to higher TDM production. Results indicate that a high yielding soybean genotype should possess larger LAI, higher TDM production ability and higher AGR at all growth stages.Keywords: Soybean seed yield, total dry mass (TDM), leaf area index (LAI), absolute growth rate (AGR), relative growth rate (RGR

Studies on some morphological characters and yield attributes of synthetic Brassica hexaploids and their parents

Allopolyploidy plays an important role in plant evolution and confers better advantages on crop growth and breeding compared to low ploidy levels. The present investigation aimed to study the synthetic hexaploid Brassica (AABBCC genome) developed from Brassica cainata (BBCC genome) and Brassica rapa (AA genome) compared to their parental genotypes considering some morphological characters, yield attributes and yield. Increased vegetative growth in hexaploids over their parents was observed. Hexaploids exhibited wider ranges with higher coefficients of variations compared to the parents for all characters studied. Hexaploids had taller plants, higher number of siliqua and larger flowers than those of both parents. Though average pollen fertility in the hexaploids was lower than both parents but out of 420 hexaploids, seventeen had comparatively higher percentages of pollen fertility as well as siliqua setting. Number of seeds per siliqua and siliqua length were found to be lower than their parents. Mean seed weight per plant in the hexaploids was lower than the parents though the hexaploids had higher number of siliquae along with higher seed weight. Days to flowering and maturity in the hexaploids were in between the parents and closer to the B. carinata parent. Five hexaploid plants from BARIBatishak-1 × Carinata-1 and two from each of Carinata-1 × BARIBatishak-1 and Agrani × Carinata-1 were found to be promising because they have higher seed yield per plant than their parents. Those nine selected high yielding hexaploid plants could be evaluated in the subsequent generations to select the stable and desirable Brassica hexaploids.Keywords: Brassica hexaploid, morphological characters, yield attribute