Assessment of different growing conditions for enhanced postharvest quality and shelf-life of leaf lettuce (Lactuca sativaL.)

ArticleLettuce is the most important leafy vegetable. It is exclusively used as freshly raw form but sometime also as cooked. However, its quality depends on several pre- and postharvest factors. The effects of growing conditions and cultivars on the postharvest quality of leaf lettuce were investigated. In this experiment the interaction of variable factor; like growing conditions and fixed factor; cultivars are also observed. The leaf lettuce cultivars ‘Cheongchima’, ‘Cheongchuckmyeon’, ‘Geockchima’ and ‘Geockchuckmyeon’ were grown under favourable (natural condition) and unfavorable growing condition (with excess soil water and 50% shading) to evaluate their shelf-life and postharvest qualities. Plant height and the number of leaves were significantly varied in different growing conditions and by cultivars. In addition, fresh weight was affected by only growing condition, whereas leaf thickness was influenced by cultivars, growing conditions and the cultivars influenced the degree of fresh weight loss and respiration rate during postharvest storage. However, the postharvest storage qualities differed with cultivars and in combination with growing conditions.Leaf thickness and quality of leaf lettuce before and after harvest were also varied by cultivars and growing conditions. It could be concluded that postharvest leaf lettuce quality remains acceptable when growing under excess soil water with 50% shading

Biotransformation of 3-hydroxydibenzo-\u3b1-pyrone into 3,8 dihydroxydibenzo-\u3b1-pyrone and aminoacyl conjugates by Aspergillus niger isolated from native "shilajit"

"Shilajit" is a panacea in Ayurveda, the Indian traditional system of medicine. The major bioactives of "shilajit" have been identified as dibenzo-\u3b1-pyrones (DBPs), its oligomers and aminoacyl conjugated derivatives. These bioactive compounds play a crucial role in energy metabolism in all animal cells including those of man. 3-hydroxydibenzo-\u3b1-pyrone (3-OH-DBP), a key DBP component of "shilajit" is converted, among other products, to another active DBP derivative, viz. 3,8-hydroxydibenzo-\u3b1-pyrone, 3,8(OH)2-DBP, in vivo, when its precursor is ingested. 3,8(OH)2-DBP is then involved in energy synthesis in the mitochondria in the reduction and stabilization of coenzyme Q10 in the electron transport chain. As the chemical synthesis of 3,8(OH)2-DBP is a complex, multi-step process and economically not readily viable, we envisioned the development of a process using microorganisms for bioconversion of 3-OH-DBP to 3,8(OH)2-DBP. In this study, the biotransformation of 3-OH-DBP is achieved using Aspergillus niger, which was involved in the humification process on sedimentary rocks leading to "shilajit" formation. A 60% bioconversion of 3-OH-DBP to 3,8(OH)2-DBP and to its aminoacyl derivatives was achieved. The products were characterized and estimated by high performance liquid chromatography (HPLC), high performance flash chromatography (HPFC) and gas chromatography-mass spectrometry (GC-MS) analyses. Among the Aspergillus species isolated and identified from native "shilajit", A. niger was found to be the most efficient for this bioconversion

Desempenho agronômico e variabilidade genética em genótipos de couve

O objetivo deste trabalho foi avaliar o desempenho agronômico de acessos de couve e estimar os parâmetros genéticos e a correlação entre características de interesse para o melhoramento. O experimento foi realizado em delineamento de blocos ao acaso, com 30 genótipos de couve, entre os quais, três cultivares comerciais, de diferentes empresas. Foram utilizadas quatro repetições, com cinco indivíduos por parcela. Verificou-se variabilidade genética entre os genótipos, com predominância dos efeitos genéticos sobre os ambientais, o que indica a possibilidade de se obterem ganhos genéticos representativos com o melhoramento. As características importantes para o melhoramento da espécie foram: comprimento e largura de folha, diâmetro de pecíolo, área foliar, altura de planta, número de brotações e massa de folhas secas. Os genótipos comerciais apresentaram menor área foliar, massa de matéria seca de folhas, altura de planta, comprimento e largura de folha, comprimento de pecíolo, e número de brotações e de folhas comerciais

Genetic divergence and genetic gain in bread wheat through selection practices

Genetic diversity is essential to meet the diversified goals of plant breeding such as producing cultivars with increased yield, wider adaptation, desirable quality, pest and disease resistance. In this study genetic diversity and selection index of 24 genotypes of bread wheat were evaluated. The performance of 24 wheat genotypes showed that there were significant variations for the characters suggesting the presence of genetic variability among the genotypes. The genotypes were grouped into five clusters viz. I, II, III, IV and V based on Mahalanobis’ D2 statistics. Cluster I and II were the largest group containing six genotypes and the rest three clusters contained four, five and three genotypes respectively. The genotyps belonging to the same group had smaller D2- value than between those belonging to different clusters. Study on selection indices through discriminate function showed that Anza ranked as the best followed by the genotypes Rawal, PBW-373 and Kheri and suggests that these highest scoring genotypes might be recommended for farmers’ cultivation for better yield and it would be expected genetic gain upto 49.77% through selection practices based on the characters studied. Therefore, a crossing programme could be made among the genotypes belonging in cluster I and cluster V will provide maximum heterotic combination, especially for yield of bread wheat. Alternatively, among the studied genotypes Anza could be cultivated for better performance

In vitro regeneration system in brinjal (Solanum melongena L.) for stress tolerant somaclone selection

Brinjal is the second most important vegetable crop after potato in Bangladesh in respect of total areas and third in production. It also plays a vital role in the national economy as a cash crop. An experiment was conducted with two cultivars of brinjal namely Jhumky and Islampuri to observe the callus induction ability of different explants-shoot tip, hypocotyl and midrib in MS basal media supplemented with different concentrations and combinations of growth regulators. The rate of callus induction from shoot tip, hypocotyl and midrib were 82.78%, 74.88% and 78.71%, respectively. Highest rate of callus induction was found in shoot tip. Variety Islampuri showed higher rate of callus induction (80.62%). Among the treatments 2mg/l NAA showed the best performance in callus proliferation. Cytokinin (0.5 mg/l BAP) showed highest percentage of shoot regeneration (57.13%). For root induction, MS basal medium was proved to be better treatment for average number (12-15) of roots. The survival rate of transferred regenerated plantlets after hardening was higher in Jhumky (80%). Regenerated plantlets from callus of both the varieties exhibited 4-9 times higher proline, 2-3 times lower vitamin C and 2-3 times higher iron (Fe) content compared to their seed derived seedlings. This experiment showed that it is possible to develop shoot and fruit borer tolerance brinjal genotypes through somatic embryogenesis that was selected based on biochemical markers within the very short period of time. These findings will be helpful for further selection of the selected variants in field condition in the next phase of the study

Genotype-environment interaction and stability analysis of four fine rice varieties

Genotype-environment interactions through different stability parameters and performance traits of four fine rice genotypes were studied. The traits were; days to 50% flowering, days to maturity, plant height (cm), number of effective tillers per hill, panicle length (cm), number of fertile grains per panicle, number of sterile grains per panicle and yield (t/ha) in four fine rice genotypes across nine environments along with experimental farm of Genetics and Plant Breeding department, Bangladesh Agricultural University (BAU) Mymensingh. Significant differences were observed for genotypes, environments and genotypes–environment interaction. Stability analysis after Eberhat and Russell’s model suggested that the genotypes used in study were more or less responsive to environmental changes. Most of the genotypes performed better in Comilla. BAU125 was found stable for effective tillers per hill and comparatively less sensitive to other genotypes in panicle length and number of sterile grains per panicle. BR5 was stable for days to maturity and plant height whereas Kalizira performed better than other genotypes for fertile grains per panicle. In general, only the genotype BAU125 was found stable for effective tillers per hill, panicle length and lowest number of sterile grains per panicle

GENETIC ANALYSIS OF SOME AGRONOMIC TRAITS IN GROUNDNUT (Arachis hypogaea L.)

A 10×10 half diallel experiment was conducted on groundnut (Arachis hypogaea L.) to ascertain the gene action and genetic parameters of ten traits including 50% flowering, no. of pods per plant, plant height, harvest index, pod index, 100 pod weight, 100 kernel weight, pod size, diseases infection and yield per plot. The experiments were carried out in the Department of Genetics and Plant Breeding, Bangladesh Agricultural University (BAU), Mymensingh during the cropping season of 2010-2011. The estimates of gene effects indicated that significance of both additive and non-additive variance for pod size, 100 pod weight and diseases infection among the traits and presence of over dominance satisfying assumptions of diallel except dormancy. However, both the additive and non-additive gene affects together importance to control of most quantitative traits in the groundnut. The average degree of dominance (H1/D) 1/2 (H1 = dominance variance, D = additive variance) was higher than one, indicating over dominance for all the traits. The narrow-sense heritability was high for 50% flowering (38%), harvest index (35%), pod size (52%), 100 pod weight (35%) and yield per plot (41%) indicating that great genetic gain could be achieved for them

Biotransformation of 3-hydroxydibenzo-α-pyrone into 3,8 dihydroxydibenzo-α-pyrone and aminoacyl conjugates by Aspergillus niger isolated from native "shilajit"

"Shilajit" is a panacea in Ayurveda, the Indian traditional system of medicine. The major bioactives of "shilajit" have been identified as dibenzo-α-pyrones (DBPs), its oligomers and aminoacyl conjugated derivatives. These bioactive compounds play a crucial role in energy metabolism in all animal cells including those of man. 3-hydroxydibenzo-α-pyrone (3-OH-DBP), a key DBP component of "shilajit" is converted, among other products, to another active DBP derivative, viz. 3,8-hydroxydibenzo-α-pyrone, 3,8(OH)2-DBP, in vivo, when its precursor is ingested. 3,8(OH)2-DBP is then involved in energy synthesis in the mitochondria in the reduction and stabilization of coenzyme Q10 in the electron transport chain. As the chemical synthesis of 3,8(OH)2-DBP is a complex, multi-step process and economically not readily viable, we envisioned the development of a process using microorganisms for bioconversion of 3-OH-DBP to 3,8(OH)2-DBP. In this study, the biotransformation of 3-OH-DBP is achieved using Aspergillus niger, which was involved in the humification process on sedimentary rocks leading to "shilajit" formation. A 60% bioconversion of 3-OH-DBP to 3,8(OH)2-DBP and to its aminoacyl derivatives was achieved. The products were characterized and estimated by high performance liquid chromatography (HPLC), high performance flash chromatography (HPFC) and gas chromatography-mass spectrometry (GC-MS) analyses. Among the Aspergillus species isolated and identified from native "shilajit", A. niger was found to be the most efficient for this bioconversion