Fused lobed anther and hooked stigma affect pollination,fertilization and fruit set in mango: A scanning electron microscopy study

Mango malformation is the most threaten disease that limits mango production, worldwide. For a long time, due to its complex nature, the cause and causal agents were strongly disputed. Diverse Fusaria, including Fusarium mangiferae, are known to be associated with the disease. There are indications that augmented level of endogenous ethylene in response to various abiotic and biotic stresses alters the morphology of reproductive organs. Here, scanning electron microscopy (SEM) of healthy and malformed reproductive organs of mango cv. Baramasi was performed to compare the functional morphology. The SEM study revealed that anthers of hermaphrodite healthy flowers were bilobed with large number of turgid pollen grains whereas malformed flowers showed fused lobed anthers with scanty deformed pollen grains. Furthermore, the stigma of healthy flowers exhibited a broad landing pad as compared to malformed stigma which showed hooked and pointed tip. All these impaired morphology of male and female reproductive organs lead to failure of sexual reproduction. This is the first evidence to show fused lobed anther with impaired pollen grains and hooked stigma with poor stigmatic receptivity are mainly responsible for restricting the pollen germination and pollen tube growth. Here we suggest that abnormal development of anthers and pistils is due to endogenously produced stress ethylene. Further, added load of cyanide, a byproduct of ethylene biosynthesis, may also contribute to the development of necrosis which lead to desiccation of anther and pistil during hypersensitive response of plants.     

Effect ofAzotobacter chroococcum on the hatching of egg masses and eggs ofMeloidogyne incognita

Summary Investigations were carried out to study the effect ofAzotobacter chroococcum VP-5 on the hatching of egg masses and eggs ofMeloidogyne incognita in vitro. Eggs were more susceptible and required lesser time for antagonistic action of Azotobacter than egg masses.     

Neutroperiodism in different varieties of groundnut with respect to zinc and its uptake as affected by phosphorus application

Summary A greenhouse experiment was conducted to study the Zn uptake at various growth stages of groundnut plant. Soil used for the study was non calcareous typic Torripsamment, low in available Zn. Results obtained revealed that highest amount of Zn was accumulated in shoot portion at midflowering and declined severely at 75 days of plant growth. Its concentration in shoot portion increased again at maturity. Maximum Zn translocation from the shoot portion to fruits occurred between 50 and 75 days growth period. P application showed an antagonistic effect on Zn uptake. re]19760213     

Single cell protein from various chemically pretreated wood substrates using Chaetomium cellulolyticum

The growth behavior of Chaetomium cellulolyticum, a new cellulolytic fungus, has been examined in slurry fermentation systems using various chemically pretreated sawdusts from hardwoods as substrates. Both acid- and alkali-pretreatment methods were used and the fermentation media included the spent pretreatment liquor in an attempt to concurrently maximize substrate utilization and minimize the biological oxygen demand (BOD) level in the process effluent. Diauxic growth patterns were found in the three cases studied, suggesting an initial utilization of soluble hemicellulose sugars followed by utilization of the insoluble cellulose. This behavior patterns was supported by separate growth experiments using the major sugars of hemicellulose as carbon sources. The organism was found to be a good convertor of both cellulose and hemicelluloses into single cell protein (SCP). In terms of rate and extent of protein production in the insoluble biomass product, acid pretreatment appears to be better than alkali pretreatment if the product is intended as ruminant feed.     

Serogenetic variation in four caste populations of Haryana, India

The phenotypes and gene frequencies of 3 blood groups, 7 red-cell enzymes and a serum protein were studied in 4 caste population groups of Haryana, North India. The results indicate that the distribution of these blood markers is rather homogeneous in the 4 groups and generally resembles that observed in various populations from neighbouring North Indian states.