nan Hisamuddin

Effect of different inoculum levels of Meloidogyne incognita on growth and yield of Lycopersicon esculentum, and internal structure of infected root

Lycopersicon esculentum (tomato) plants, grown in sterilised clay pots, were inoculated with 50, 500, 1000, and 3000 second-stage juveniles (J2) of the root-knot nematode (Meloidogyne incognita) and were kept in a greenhouse. A non-significant reduction in plant growth and yield was noticed in T1 plants. Significant reductions in plant growth and yield were found in T2, T3, and T4 plants. Highest reductions, in growth and yield, were observed in T5 plants. Transverse and longitudinal sections revealed that M. incognita traversed through the cortical tissues of the root, caused infection in the differentiating vascular tissues and successfully established in the infected roots. The post-infection changes in the affected parts were hypertrophy and hyperplasia, around the head of the nematodes. Five to 10, among the hypertrophied cells, developed into very large, multinucleate, prominent, and highly specialised giant cells. The nuclei in each giant cell enclosed one or more nucleoli. Xylem and the phloem strands were found to be disoriented. Abnormal xylem and phloem comprised a substantial portion near the giant cells. The metabolic changes in the affected part led to the formation of galls, characteristic of the root-knot infection.

Study on Black Gram (Vigna mungo L.) Infected with Meloidogyne incognita under the Influence of Pseudomonas fluorescens, Bacillussubtilis and Urea

Pot studies were carried out to assess the growth and biochemical components of Vigna mungo L. cultivar ‘Azad- 2’ with the root-knot nematode and treated with two biofertilizers viz. Pseudomonas fluorescens strain CHA0, and Bacillus subtilis strain Bs-5. The plants were grown in soil at N50 and N100 doses of urea. Uninoculated untreated plants served as control. From the results, it was evident that V. mungo plants exhibited profused vegetative growth at N100 dose of urea as was observed in the treatment 5. The plants of treatment 5 were inoculated with P. fluorescens CHA0 (20 ml). The number of nodules per plant was found increased to 14.33 per plant, total chlorophyll content by 2.91 mg/g of leaf tissue, leghaemoglobin by 3.81 mg/g, and protein content in leaves and seeds by 0.83 and 0.76 mg/g, respectively, when compared with the control and the plants that received different doses of B. subtilis Bs-5 in the absence of the root-knot nematode. Significant reduction in gall number (41.66) and number of nematodes per gram of root (4.66) was recorded in the treatment 5.

Management of Root-Knot Disease in Phaseolus vulgaris Using Potassium Fertilizer and Biocontrol Agents

The experiment was conducted to determine the effect of different doses of potassium fertilizer (K2O) along with the biofertilizers, Trichoderma harzianum, and Pochonia chlamydosporia, in the management of the root-knot disease caused by the root-knot nematode (Meloidogyne incognita) and on the growth and physiological parameters of Phaseolus vulgaris. From the result it was observed that the application of potassium along with biofertilizers in the treatment T-7 in which plants were treated with double dose of potassium along with both fungal biocontrol agents and root-knot nematode, improved all the growth as well as biochemical parameters viz, chlorophyll, protein, nitrate reductase, nitrogen and phosphorus contents and reduced the number of galls per root system in comparison to the control and other treatments.

Effect of bark extract of different plant species on the hatching of Meloidogyne incognita

An in vitro experiment was conducted to evaluate the effect of bark extract of different plant species viz., Azadirachta indica, Acacia nilotica, Emblica officinalis, Eucalyptus citriodora, Mangifera indica and Terminalia arjuna at varying concentration levels S, S/2, S/10 and S/100 on the hatching of Meloidogyne incognita. One hundred per cent inhibition was observed with Azadirachta indica under both un-decomposed and decomposed conditions. The effect was decreased with Acacia nilotica, Emblica officinalis, Eucalyptus citriodora, Mangifera indica and Terminalia arjuna, respectively. Effect of decomposed bark extract on hatching was more pronounced as compared to un-decomposed bark extract.

Histology of the interactions of Paecilomyces lilacinus with Meloidogyne incognita on Eclipta alba (L.)

Abstract Under greenhouse conditions, the experiment was conducted to test the efficacy of opportunistic and nematophagous hyphomycete, Paecilomyces lilacinus against root-knot nematode, Meloidogyne incognita on Eclipta alba. The treatment comprised inoculation of E. alba with M. incognita alone (N) and in combination with P. lilacinus (one week before (T1), simultaneously (T2), one week after (T3), two weeks after (T4) and three weeks after (T5)). The results showed that the application of P. lilacinus before one week of nematode inoculation (Tl) was more effective than other treatments. A significant enhancement was noticed in the growth and yield of E. alba. Root-knot and egg mass indices were suppressed due to destruction of the mature females and the egg masses. Histopathological studies revealed the presence of P. lilacinus hyphae in and around the females and the eggs.

Studies on the Histopathological Responses of Vigna Mungo towardsMeloidogyne Incognita at Different Time Intervals

The pot experiments on Vigna mungo with five replicates for each treatment were set up in the Department of Botany, Aligarh Muslim University, Aligarh, Uttar Pradesh (27°52’59” N to 78°04’59” E; 180 m above sea level), India. Histological studies of the roots of infected plants were carried out after 24 h, 48 h, 72 h, 5 days, 10 days, 15 days, 21 days, 25 days and 30 days of inoculation. The second-stage juveniles penetrated into the roots and moved intercellularly by separating the cell walls after 24 h. The first sign of infection observed after 48 h of inoculation was hypertrophy in the cells, around the head of the juvenile. The cytological changes in the hypertrophied cells became more prominent after 72 h of inoculation, and the cells transformed into discrete giant cells. The giant cell cytoplasm became dense and stained darkly, the size of the nuclei and the nucleoli increased after five days of inoculation. Ten days after inoculation, the width of vessel elements was also increased. The second-stage juveniles moulted into the third stage. After 21 days of nematode exposure, the hypertrophied and hyperplastied parenchyma cells were observed adjacent to the giant cells. At several occasions, the giant cell complexes appeared to be surrounded by abnormal xylem comprising of abnormal vessel elements, which were transformed from the hypertrophic and hyperplastic parenchymatous tissue. The head region of the nematode was in contact with the giant cells while remaining part of the body expanded and caused disruptions in the arrangement of vascular and cortical tissues, as was observed after 25 days of inoculation. After 30 days of nematode inoculation, egg masses were found associated with all the mature females. The tissues were disrupted as the egg masses were pushed out to the surface of the root. Several eggs enclosed first stage juveniles.

In Vitro Studies on Phytochemical Screening of Different Leaf Extractsand Their Antifungal Activity against Seed Borne Pathogen Aspergillusniger

In the present study, screening of aqueous extracts obtained from five medicinally active plants (Melia azedarach, Cassia siamea, Murraya koenigii, Jatropha curcas and Delonix regia) was performed against Aspergillus niger, a causative agent of different destructive diseases of plants. The extracts were also used for the phytochemical screening following Horborne method. The results obtained from this study demonstrated occurrence of alkaloids, tannins, saponins, flavonoids, phenolics, amino acids and terpenes, in the aqueous leaf extract. To obtain an optimum concentration of the extracts, for inhibition of Aspergillus niger, 10%, 15% and 20% concentrations of all the five plants were prepared. The three plants viz., M. azedarach, C. siamea and M. koenigii showed antifungal activity against A. niger in all the concentrations. Inhibition of mycelial growth was lowest at the concentration of 20% of D. regia followed by J. curas. The present protocol showed that the growth of A. niger was inhibited to greater extent at 20% than at lower concentrations of the extracts. It could be suggested that plant extracts could possibly be exploited for the management of seed-borne pathogenic fungi to prevent biodeterioration of seeds in an eco-friendly way.

The effect of Meloidogyne incognita on the histopathology of Momordica charantia roots

Bitter gourd (Momordica charantia L.) was inoculated with root-knot nematode Meloidogyne incognita to investigate the anatomical abnormalities in the affected roots. Soon after inoculation the second-stage juveniles (J2) entered at or near the root caps and migrated intercellularly towards the zone of vascular differentiation. Discrete giant cells were observed after three days of inoculation. The nematode induced hypertrophy and hyperplasia near the giant cells. After six days, the juveniles moulted to their third stage (J3). At the same, time giant cell size and density of giant cell cytoplasm increased. The continuity of vascular strands remained unaffected. Between 12 and 24 days of inoculation the giant cells enlarged several times and became multinucleate and enclosed dense and granular cytoplasm. The nematodes became almost pyriform 18 days after inoculation. The orientation of vascular strands changed, due to hypertrophy, hyperplasia and enlargement of the nematode. After 30 days of inoculation the nematodes developed into mature females and started egg laying. A large amount of parenchyma transformed into abnormal xylem.

Effects of Eclipta alba on the morphometrics of root-knot nematode, Meloidogyne incognita as influenced by fly ash amended soil.

An experiment in a complete randomised design was conducted with the aim of investigating the impact of graded quantities (10, 20, 30, 40 and 50%) of fly ash on the morphometrics of root-knot nematode, Meloidogyne incognita (2000 J2/pot) in Eclipta alba. The application of fly ash brought about deleterious effects on the development of the nematode which were reflected on dimensions of the mature females in all the fly ash concentrations over the inoculated control (IC). Significant reductions in length and width of body, neck, stylet and median bulbs of the mature females were recorded at higher (40 and 50%) fly ash levels, when compared with inoculated control (IC). The severity of root-knot disease was found to be decreased with increasing fly ash concentrations.