Crecimiento y eficiencia fotoquímica del fotosistema II en plántulas de 2 variedades de Capsicum annuum L. inoculadas con rizobacterias u hongos micorrícicos arbusculares / Growth and photochemical efficiency of photosystem II in seedlings of two varieties of Capsicum annuum L. inoculated with rhizobacteria and arbuscular mycorrhizal fungi

Una alternativa para el manejo sustentable en el cultivo de Capsicum annuum L. se ha enfocado en el uso de bacterias promotoras del crecimiento vegetal (BPCV) y hongos micorrícicos arbusculares (HMA). Esta investigación seleccionó BPCV y HMA sobre la base de su efecto en plantas de chile Bell Pepper y jalapeño. Se utilizaron 5 cepas bacterianas aisladas de diferentes localidades del estado de México (P61 [Pseudomonas tolaasii], A46 [P. tolaasii], R44 [Bacillus pumilus], BSP1.1 [Paenibacillus sp.] y OLs-Sf5 [Pseudomonas sp.]) y 3 tratamientos con HMA (H1 [consorcio aislado de la rizosfera de chile en el estado de Puebla], H2 [Rhizophagus intraradices]y H3 [consorcio aislado de la rizosfera de limón del estado de Tabasco]). Además, se incluyó un tratamiento fertilizado (solución Steiner 25%) y un testigo absoluto. Plántulas de chile jalapeño «Caloro¼ y pimiento Bell Pepper «California Wonder¼ fueron inoculadas con HMA en el momento de la siembra y con BPCV 15 días después de emerger, y crecidas bajo condiciones de cámara de ambiente controlado. En chile jalapenño, la mejor cepa bacteriana fue P61 y el mejor tratamiento de HMA fue el H1; en Bell Pepper la mejor cepa fue R44 y los mejores HMA fueron el H3 y el H1. Estos microorganismos incrementaron el crecimiento de plántulas de chile jalapenño y Bell Pepper en comparación con el testigo sin fertilizar. Asimismo, P61 y R44 beneficiaron positivamente la capacidad fotosintética del PSII.

Plant growth promoting rhizobacteria (PGPR) and arbuscular mycorrhizal fungi (AMF) are a biological alternative for the sustainable management of Capsicum annuum L. This research work evaluated the effects of both PGPR and AMF on bell pepper and jalapeno pepper plants. Five bacterial strains isolated from several locations in Estado de Mexico were used: [P61 (Pseudomonas tolaasii), A46 (P. tolaasii), R44 (Bacillus pumilus), BSP1.1 (Paenibacillus sp.), and OLs-Sf5 (Pseudomonas sp.)], and three treatments with AMF [H1 (consortium isolated from pepper crops in the State of Puebla), H2 (Rhizophagus intraradices), and H3 (consortium isolated from the rhizosphere of lemon trees, State of Tabasco)]. In addition, a fertilized treatment (Steiner nutrient solution at 25%) and an unfertilized control were included. Seedlings of "Caloro" jalapeno pepper and "California Wonder" bell pepper were inoculated with AMF at seed sowing, and PGPR were inoculated after 15 days of seedling emergence; seedlings were grown under plant growth chamber conditions. P61 bacterium and H1 AMF consortia were the most effective microorganisms for jalapeno pepper whereas R44 bacterium and AMF H3 and H1 were the most effective for bell peppers, when compared to the unfertilized control. Furthermore, P61 and R44 bacteria showed beneficial effects on PSII efficiency.

Plant growth promoting capability and genetic diversity of bacteria isolated from mud volcano and lime cave of Andaman and Nicobar Islands

Twenty four bacterial strains from four different regions of mud volcano and lime cave were isolated to estimate their diversity, plant growth promoting and biocontrol activities to use them as inoculant strains in the fields. An excellent antagonistic effect against four plant pathogens and plant growth promoting properties such as IAA production, HCN production, phosphate solubilization, siderophore production, starch hydrolysis and hydrolytic enzymes syntheses were identified in OM5 (Pantoea agglomerans) and EM9 (Exiguobacterium sp.) of 24 studied isolates. Seeds (Chili and tomato) inoculation with plant growth promoting strains resulted in increased percentage of seedling emergence, root length and plant weight. Results indicated that co-inoculation gave a more pronounced effects on seedling emergence, secondary root numbers, primary root length and stem length, while inoculation by alone isolate showed a lower effect. Our results suggest that the mixed inocula of OM5 and EM9 strains as biofertilizers could significantly increase the production of food crops in Andaman archipelago by means of sustainable and organic agricultural system.

Endogenous GUS-like activity in Capsicum chinense Jacq

The gene uidA, codes for beta-glucuronidase, which is one of the reporters more frequently utilized in transgenic plants. However, this can only be use if the selected organism does not present endogenous GUS-like activity. In tissues of C. chinense we found a GUS-like activity showing different levels of intensity. Histochemical screening showed that endogenous GUS-like activity decreased, or reduced significantly, in almost all tissues with exception of stament, when phosphate buffer was adjusted to pH 8. Subsequently, C. chinense zygotic embryo explants were transient transformed with Agrobacterium tumefaciens LBA4404 (pCAMBIA2301) and plantlets regenerated were histochemically stained in phosphate buffer pH 8. Observations of incubated tissues of C. chinense regenerants showed blue staining, suggesting expression of uidA. Incubated tissues of non-transformed regenerants did not show blue staining in phosphate buffer pH 8. The results show that for transformation experiments of C. chinense with uidA gene, pH 8 is recommended for histochemical staining.