Beyond survival: unraveling the adaptive mechanisms of cucurbit weeds to salt and heavy metal stress through biochemical and physiological analyses / Além da sobrevivência: desvendando os mecanismos adaptativos de ervas daninhas cucurbitáceas ao sal e estresse de metais pesados por meio de análises bioquímicas e fisiológicas

Salt stress and heavy metal are instigating hazard to crops, menace to agricultural practices. Single and combined stresses affecting adversely to the growth and metabolism of plants. To explore salt and heavy metal resistant plant lines as phytoremediants is a need of time. Physiological responses are main adaptive responses of the plants towards stresses. This response varies with species and ecotype as well as type and level of stress. Two cucurbit weeds from two ecotypes were selected to evaluate their physiological adaptations against independent and combined stresses of various levels of salt (NaCl) and heavy metal (NiCl2). Various physiological parameters like water potential, osmotic potential, pressure potential, CO2 assimilation rate, stomatal conductance, chlorophyll a and b, carotenoids, and production of adaptive chemicals like SOD, CAT, proteins, sugars and proline were studied. Citrullus colocynthis showed more adaptive response than Cucumis melo agrestis and desert ecotype was more successful than agricultural ecotype against stresses.

O estresse salino e os metais pesados são um perigo instigante para as plantações e uma ameaça para as práticas agrícolas. Estresses simples e combinados afetam adversamente o crescimento e o metabolismo das plantas. Explorar linhagens de plantas resistentes a sais e metais pesados como fitorremediantes é uma necessidade de tempo. As respostas fisiológicas são as principais respostas adaptativas das plantas aos estresses. Essas respostas variam de acordo com a espécie e o ecótipo, bem como com o tipo e o nível de estresse. Duas plantas daninhas cucurbitáceas de dois ecótipos foram selecionadas para avaliar suas adaptações fisiológicas frente a estresses independentes e combinados de vários níveis de sal (NaCl) e metal pesado (NiCl2). Vários parâmetros fisiológicos, como potencial hídrico, potencial osmótico, potencial de pressão, taxa de assimilação de CO2, condutância estomática, clorofila a e b, carotenoides e produção de produtos químicos adaptativos, por exemplo, SOD, CAT, proteínas, açúcares e prolina, foram estudados. Citrullus colocynthis apresentou resposta mais adaptativa do que Cucumis melo agrestis e o ecótipo deserto foi mais bem-sucedido do que o ecótipo agrícola contra estresses.

Efficacy of Aluminum Sulfate Addition to Poultry Litter on Productive Performance of Laying Hens, Ammonia Emissions, and Litter Quality

The objective of this research was to examine whether different types of litter (New, used, and mixed) and alum could interfere in litter quality, thereby also influencing the productive performance of laying hens. A total number of 450 Inshas chickens aged 24 weeks were randomly distributed into six groups (5 replicates, each with 15 hens) of floor litter. The groups included (G1) new wheat straw litter, (G2) used wheat straw litter, (G3) mixed wheat straw litter (50% new+50% used) and (4, 5 and 6) the same litter types in groups 1, 2 and 3 supplied with 500g of alum /m2 litter. The experiment lasted 16 weeks. Laying hens productive parameters, blood parameters, carcass parameters, respiratory rate, coliform count and pH, as well as ammonia emission, litter quality were assessed.The results showed that the litter type significantly affects the level of ammonia emission, litter characteristics, carcass characteristics, intestinal pH and coliform count, blood characteristics (T3, cholesterol, uric acid, total protein, albumin, globulin, hemoglobin, and PCV), as well as the body weight gain. In general, we found that reused litter followed by the mixed litter without added alum resulted in the lowest efficiency on the studied traits, as compared to the same types of litter treated with alum and the new litter. We therefore conclude that the addition of alum reduces ammonia emission and improves the characteristics of the litter, which is reflected in enhancement of productive performance and properties of blood and carcass.(AU)