Androgynomonoecious Jatropha curcas: Chromosomes, Isozymes, and Flowers Gender

Jatropha curcas (J. curcas) is usually monoecious plants, which have male and female flowers on the same inflorescence. However, J. curcas can be found as an androgynomonoecious plant (have male, female, and hermaphrodite flowers), even though very rare. Androgynomonoecious J. curcas can be identified after six months of planting when it had started flowering. Therefore, it is important to identify the characteristics of androgynomonoecious J. curcas that can differentiate between androgynomonoecious and monoecious plants in earlier stages of growth. The objectives of the research were to observe isozymes, chromosome and flowers gender of androgynomonoecious and monoecious J. curcas Banten and Lampung accessions. Seeds from five genotypes of J. curcas were used in the research. The observation was carried out on the chromosome and isozymes (Peroxidase and Esterase isozymes) could be used as markers to differentiate androgynomonoecious and monoecious plants. Observations about the flower gender from offsprings derived from different seeds were important to know the inheritance of flower gender. The androgynomonoecious and monoecious J. curcas were diploid with number of chromosomes 2n=2x=22. The chromosomes of androgynomonoecious have longer than that of monoecious J. curcas. The isozymes of androgynomonoecious J. curcas had four alleles and monoecious J. curcas (Banten female monoecious) had three alleles. The flower inflorescence and gender derived from androgynomonoecious plants were unstable, due to androgynomonoecious is intermediate state.

Meloidogyne and Pratylenchus species in sugarcane fields in the state of Alagoas, Brazil

ABSTRACT: The objective of this study was to accomplish a survey on populations of Meloidogyne and Pratylenchus species in sugarcane farming areas in the state of Alagoas, Brazil. Twenty samples of soil and roots were processed to extract and quantify nematodes; however, the identification of Meloidogyne species was performed using only 12 samples. Pratylenchus spp. were reported at moderate population levels of 68-1556 specimens 50g-1 of roots and 2-298 specimens 100cm-3 of soil in twenty analyzed samples. For Meloidogyne spp., these values were of 12-487 specimens 50g-1 of roots and 0-140 specimens 100cm-3 of soil. Based on electrophoresis of esterase isozymes, M. incognita was reported to be the most frequent species, followed by M. javanica and M. arenaria. Pratylenchus species identified through morphometrical and morphological characteristics were P. zeae and P. brachyurus , with predominance for the first species. No significant correlation (P≤0.05) were reported between nematode populations and sugarcane cropping systems.

Effects of jinggangmycin on peroxidase and esterase isozymes and phytotoxin from Rhizoctonia solani AG-1 IA, the causal agent of rice sheath blight. Pirinç kabuğu yanığı nedeni Rhizoctonia solani AG-1 IA tarafından üretilen peroksidaz, esteraz izozimleri ve fitotoksinler üzerinde jinggangmycin etkisi

Objective: To explore the effects of jinggangmycin on the pathogenicity of rice sheath blight.Methods: The effects of jinggangmycin on peroxidase and esterase isozymes from Rhizoctonia solani Kuhn AG-1 IA were compared using non-denaturing polyacrylamide gel electrophoresis (PAGE). Rs-toxins were obtained from the improved Richard medium amended with jinggangmycin at different concentrations. Subsequently, bioassays of Rs-toxin, including virulence to rice tissues, seedling wilting and inhibition to the seed germination were conducted.Results: The results of PAGE showed that when the jinggangmycin concentration increased to 50 μg/mL, two of peroxidase isozyme bands became apparently weaker compared with the controls, indicating that jinggangmycin could considerably weaken the activity of the peroxidase isozyme. In addition, three extra bands of esterase isozyme were induced by jinggangmycin when the concentration increased to 50 μg/mL, indicating that jinggangmycin could affect the metabolism of esterase isozyme. The bioassays of Rs-toxin showed that jinggangmycin could weaken the virulence of Rs-toxin in rice tissues.Conclusion: It was concluded that the control role of jinggangmycin in rice sheath blight might be due to the effects of jinggangmycin on the peroxidase and esterase isozymes and Rs-toxin virulence.

Tissue distribution of esterase isozymes and their responses to cypermethrin in three macrobrachium species

In recent times prawn grounds are getting contaminated with an increased use of agricultural pesticides. Esterases play an intermediary role in conferring or in contributing to insecticide resistance. Hence, Esterase isozyme variability was studied in three Macrobrachium species (M. rosenbergii, M. malcolmsonii and M. lamarrei) on 7.5% PAGE with ? and ? naphthyl acetate as substrate in terms of number of bands, staining intensity and toxicity effects. Expression of esterase isozymes was studied in five different tissues (eye, muscle, nerve cord, stomach and hepatopancreas) where four esterase bands (Est-1, Est-2, Est-3 and Est-4) were observed in M. rosenbergii and M. lamarrei and two bands (Est-1 and Est-4) in M. malcolmsonii. Bands in the hepatopancreas of M. rosenbergii, in the eye of M. lamarrei and in the nerve cord of M. malcolmsonii were highly intense indicating higher esterase activity. It was also noticed that the slowest bands with higher molecular weight were more expressed than the others and spreading area of a particular band was not fixed in all the tissues. To observe the impact of insecticide on esterases all five tissues were exposed to 1000 ppm of cypermethrin for 24 hours and was subjected to PAGE, it was found that treated samples showed less esterase expression. Only the muscle tissues from three species were exposed to a range of doses (0.078-1000 ppm), species specific fluctuation of esterase activity was observed in an irregular fashion. Bioassay conducted with cypermethrin on M. lamarrei indicated that LC50 was 0.05ppm at 2 hours. Fluctuation of esterase activity was observed with time and dose concentrations in post mortal electrophoretic assay. DOI: http://dx.doi.org/10.3329/jasbs.v38i2.15614 J. Asiat. Soc. Bangladesh, Sci. 38(2): 227-235, December 2012

Genetic Polymorphism Based on β-napthyl Acetate in Different Age Group of Gambusia Affinis in Bangladesh

Genetic polymorphism of esterase isozymes was examined in different developmental stages of Gambusia affinis after staining with ?-napthyl acetate as substrate by 7.5% polyacrylamide gel electrophoresis. Samples were just after birth, seven, 14 days old fry, 21, 28, 35, 42, 49 days old male and female. Altogether three esterase bands named as Est-1, Est-2 and Est-3 were observed. Est-1 was absent in seven samples out of 13, Est-2 was absent only in just after birth, Est-3 was absent in seven different samples out of 13 samples. This result indicates that Est-1 and Est-3 were less active and Est-2 was very active at ? napthyl acetate. DOI: http://dx.doi.org/10.3329/jbas.v36i1.10917 Journal of Bangladesh Academy of Sciences, Vol. 36, No. 1, 39-44, 2012