Effect of a novel edible composite coating based on gum arabic and chitosan on biochemical and physiological responses of banana fruits during cold storage

The composite effects of gum arabic (GA) (5, 10, 15, and 20%) and chitosan (CH) (1.0%) on the biochemical and physiological characteristics of banana fruits stored at 13 ± 1 °C and 80 ± 3% relative humidity (RH) for 28 days and afterward for 5 days at simulated marketing conditions (25 °C, 60% RH) were investigated. Significant (P ≤ 0.05) differences were observed for the entire GA plus CH treatments as compared to the control. However, the results showed that after 33 days of storage, the weight loss and soluble solids concentration of fruits treated with 10% GA plus 1.0% CH composite coating were 24 and 54% lower, whereas fruit firmness, total carbohydrates, and reducing sugars were 31, 59, and 40% higher than the control, respectively. Furthermore, the composite edible coating of 10% GA plus 1.0% CH delayed color development and reduced the rate of respiration and ethylene evolution during storage as compared to the control. Similarly, sensory evaluation results also proved the effectiveness of 10% GA plus 1.0% CH composite coating by maintaining the overall quality of banana fruits. Consequently, the results of scanning electron microscopy also confirmed that the fruits coated with 10% GA plus 1.0% CH composite edible coating had very fewer cracks and showed a smooth surface. These findings suggest that 10% GA plus 1.0% CH as an edible composite coating can be used commercially for extending the storage life of banana fruits for up to 33 days.     

阿拉伯胶和香精油对香蕉及番木瓜贮藏过程中炭疽病及品质的控制效果

严格控制由刺盘孢属(Colletotrichum spp.)真菌引起的炭疽病对减少热带水果工业的经济损失十分重要。本文主要研究了阿拉伯胶(GA)(10%)、柠檬香草精油(LG)(0.05%)、肉桂精油(CM)(0.4%)及其复合组分在试验条件下对离体与活体香蕉和番木瓜炭疽病菌的抑制活性。结果表明,0.05%的LG和0.4%的CM对于引起香蕉和番木瓜炭疽病的两种病原菌Colletotrichum musae和Colletotrichum gloeosporioides分别具有抑制活性;单独GA处理并未表现出抑菌活性,但将0.05%LG、0.4%CM与10%GA混合处理则具有较大的抑菌活性;在各处理中,以PDA培养基中加入10%GA及0.4%CM的处理对C.musae和C.gloeosporioides这两种病原菌抑制活性最显著,对于两种病原菌菌丝生长抑制率分别为73.4%和70.0%,对孢子萌发抑制率分别为88%和85%。活体试验结果也表明,10%GA结合0.4%的CM处理具有最佳的作用效果,对C.musae和C.gloeosporioides的抑制方面表现出较强的增效作用,对人工接种的香蕉和番木瓜炭疽病导致的腐烂抑制率分别为80%和71%。品质评价的试验结果也表明,10%GA结合0.4%CM的涂膜处理具有良好效果,果实失重率、硬度、可溶性固形物和可滴定酸含量的变化均表明该处理可显著推迟果实的成熟。上述结果表明,10%阿拉伯胶结合0.4%肉桂精油处理可以作为控制诸如香蕉和番木瓜等常见热带水果采后炭疽病的生物杀菌剂。     

Bio-Efficacy of Microbial Infused Rice Straw Compost on Plant Growth Promotion and Induction of Disease Resistance in Chili

ABSTRACT

Microbial fortified organic amendment in chili cultivation may affect plant development and disease suppression. Microbial infused rice straw compost, commercial rice straw compost, and fungicide Benomyl for chili (Capsicum annum L.) cultivation and control of Sclerotium foot rot were studied under glass house condition. Chili seed cv. Kulai were sown in the Sclerotium rolfsii infested and non-infested soil. After two weeks, five healthy seedlings were transplanted into planting bags. Growth performance and development of disease symptoms associated with S. rolfsii foot rot infection were assessed. Applying microbial infused rice straw compost increased seed germination and plant growth, and suppressed development of foot rot compared to using commercial rice straw compost and the Benomyl. A higher disease reduction (84.6%) occurred with 15 Mg · ha^?1 microbial infused rice straw compost (62.7%), followed by Benomyl (53.8%), and 15 Mg · ha^?1 commercial rice straw compost (46.2%). Application of microbial infused rice straw compost at 15 Mg · ha^?1 yielded optimum seed germination and seedling establishment, plant growth, and disease suppression. Microbial infused rice straw compost is a good alternative to chemical fungicide in controlling Sclerotial disease in chili.     

Evaluation of the production potential of Macrobrachium rosenbergii (de Man) in monoculture and in polyculture with Nile tilapia and common carp in Saudi Arabia

The feasibility of polyculture of Macrobrachium rosenbergii (de Man) with two fish species, Nile tilapia, Oreochromis niloticus (L.), and common carp, Cyprinus carpio L., was examined and compared with monoculture of M. rosenbergii in 100-m² ponds. Overall percentage of females (56.8%) was higher than that of males (43.2%). The proportions of females, males and their morphotypes did not differ significantly between monoculture and polyculture. After 196 days of culture, the mean harvest weight of prawns in monoculture (30.2 g) was significantly greater than that in polyculture (21.3 g). Yield in monoculture (1152 kg ha^-1) was significantly greater than (1.62 times) that of polyculture (711 kg ha^-1). Total yield from polyculture including yield of tilapia (2544 kg ha^-1) and common carp (2999 kg ha^-1) was almost five times as great as that of prawn monoculture. Survival and food conversion rate of M. rosenbergii did not differ significantly between monoculture and polyculture.     

Gametogenic patterns of the larviparous oyster Ostrea nomades from Karachi, Pakistan (northern Arabian Sea)

The larviparous oyster Ostrea nomades from two different localities was examined histologically and found to be mostly hermaphroditic. However, pure males, pure females and indifferent oysters were also found. The hermaphrodites of O. nomades were classified into three categories: ambisexual, predominantly female and predominantly male. Gonadal development appears to take place throughout the year with increasing activity and ripening in the winter months, leading to immediate spawning and later resorption. The number of brooding larvae of O. nomades was low at both collection sites.     

Ploidy manipulation in guinea grass (Panicum maximum Jacq., Poaceae) utilizing a Hybridization-supplemented Apomixis-components Partitioning Approach (HAPA)

Ploidy manipulations are achieved by utilizing unreduced gametes, somatic chromosome doubling or haploidization. Apomixis, the asexual mode of reproduction through seeds, involves two of these phenomena viz., apomeiosis (unreduced embryo-sac formation) and parthenogenesis (fertilization-independent embryogenesis). The two components when partitioned may yield high frequencies of triploids and haploids, and thus, serve as a tool to manipulate ploidy levels when appropriately supplemented with hybridization schemes. Utilizing this H ybridization-supplemented A pomixis-components P artitioning A pproach (HAPA), the largest ploidy series in a crop plant was generated in guinea grass ( Panicum maximum Jacq.). Eighty-nine diverse guinea grass accessions were characterized for their reproductive capacities to identify tetraploid (2 n  = 4 x  = 32) accession(s) with high apospory but reduced parthenogenetic capacity, thereby producing a high frequency of hexaploid seeds. Seeds from accession IG 04-164 were utilized to produce a ploidy series by appropriately combining partitioned apomixis components and hybridizations in two seasonal cycles. We successfully obtained plants representing ploidies 3 x, 4 x , 5 x , 6 x , 8 x and 9 x , all derived from a single 4 x progenitor. Production methodology, reproducibility and utilization of HAPA in cytogenetic and molecular studies are discussed.     

Responses of enriched populations of feline T and B lymphocytes to mitogen stimulation.

Lymphocytes from healthy adult cats were separated into T and B cell-enriched subfractions by centrifuging rosetted cells on sodium metrizoate/Ficoll gradients. The responsiveness of unseparated lymphocytes (T + B), and T and B cell-enriched subfractions to stimulation with mitogens (phytohemagglutinin-P (PHA-P), concanavalin A (ConA), and pokeweed mitogen (PWM) was tested. Cultures of unseparated lymphocytes and those enriched in T cells showed similar responsiveness of PHA, ConA, and PWM stimulation; however, only a weak response to ConA and PWM was observed in B cell-enriched cultures. The mitogenic effects of PHA-P, ConA, and PWM on feline lymphocytes appeared to be due primarily to T-cell activation.     

Metabolic changes in the air-breathing fish Anabas scandens on long-term exposure to endosulfan

The long-term effect of endosulfan on the carbohydrate metabolites of the fish Anabas scandens was studied. Exposure of fish to a sublethal concentration of 6 ppb, for a period of 21 days resulted in marked changes in total carbohydrate, glycogen, lactic acid, and pyruvic acid content of the tissues. Lactate levels were found to be elevated, whereas pyruvate and glycogen content of the tissues declined. The results indicate that exposure of fish to endosulfan leads to metabolic adaptations to suit the functional need of the animal.     

Effect of roots aqueous extract of Delphinium denudatum on morphine-induced tolerance in mice

The aqueous extract of Delphinium denudatum (Dd) roots showed a significant effect against morphine- (10 mg/kg) induced tolerance and dependence in mice. Oral administration of the extract (200-1600 mg/kg) showed a significant dose-dependent inhibition of naloxone- (1 mg/kg) induced withdrawal.