Association and Linkage Analysis of Aluminum Tolerance Genes in Maize

Aluminum (Al) toxicity is a major worldwide constraint to crop productivity on acidic soils. Al becomes soluble at low pH, inhibiting root growth and severely reducing yields. Maize is an important staple food and commodity crop in acidic soil regions, especially in South America and Africa where these soils are very common. Al exclusion and intracellular tolerance have been suggested as two important mechanisms for Al tolerance in maize, but little is known about the underlying genetics. linkage populations with approximately 200 individuals each were used to study genetic variation in this complex trait. Al tolerance was measured as net root growth in nutrient solution under Al stress, which exhibited a wide range of variation between lines. Comparative and physiological genomics-based approaches were used to select 21 candidate genes for evaluation by association analysis.). These four candidate genes are high priority subjects for follow-up biochemical and physiological studies on the mechanisms of Al tolerance in maize. Immediately, elite haplotype-specific molecular markers can be developed for these four genes and used for efficient marker-assisted selection of superior alleles in Al tolerance maize breeding programs

Experimental culture of the river prawn Macrobrachium americanum larvae (Bate, 1868), with emphasis on feeding and stocking density effect on survival [Cultivo experimental de larvas de langostino Macrobrachium americanum (bate, 1868), con énfasis en alimentación y efecto de la densidad sobre la supervivencia]

The cauque river prawn Macrobrachium americanum occurs along the Pacific coast of America. This prawn can grow to a large size, making it an interesting option for aquaculture production. Currently, supplies of juveniles are limited because hatchery and laboratory-reared larvae are difficult to raise. This study assesses larval survival for different combinations of stocking density and feeding from larvae cultivated in green water. From these combinations, larvae fed with Artemia nauplii and maintained at a density of 50 larvae L-1 had the highest survival

Experimental culture of the river prawn Macrobrachium americanum larvae (Bate, 1868), with emphasis on feeding and stocking density effect on survival [Cultivo experimental de larvas de langostino Macrobrachium americanum (bate, 1868), con énfasis en alimentación y efecto de la densidad sobre la supervivencia]

The cauque river prawn Macrobrachium americanum occurs along the Pacific coast of America. This prawn can grow to a large size, making it an interesting option for aquaculture production. Currently, supplies of juveniles are limited because hatchery and laboratory-reared larvae are difficult to raise. This study assesses larval survival for different combinations of stocking density and feeding from larvae cultivated in green water. From these combinations, larvae fed with Artemia nauplii and maintained at a density of 50 larvae L-1 had the highest survival

Contributions to the biology of molting and growth of the longarm river prawn Macrobrachium tenellum (Decapoda: Paleamonidae) in Mexico

Studies on the molting cycle of Macrobrachium tenellum are not available, which limits the scope of studies of growth and reproduction. The duration of the molt cycle was determined under controlled experimental conditions. The prawns were divided into four groups according to weight: Group 1 (1.0-1.9 g), Group 2 (2.0-2.9 g), Group 3 (3.0-3.9 g), and Group 4 (4.0-9.0 g). The increase in total weight was higher in groups 2 (23.4%) and 3 (20.3%) than in group 1 (~18%) and 4 (~18%). The increase in size after molting among all groups was statistically different: in group 1 it increased 6.1% (highest) and in group 2 it increased 2.2% (lowest). The duration of a complete cycle was 8.9, 9.4, 10.4, and 15.1 days for groups 1, 2, 3, and 4, respectively. The lengths of the molting cycles were not significantly different between groups 1 and 2, but group 4 was different from group 1

Establishing the International Genetic Discrimination Observatory

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