physiological and biochemical changes in guava psidium guajava l infested by root knot nematode meloidogyne enterolobii yang eisenback 1983

Abstract

ABSTRACT newlinePHYSIOLOGICAL AND BIOCHEMICAL CHANGES IN GUAVA (PSIDIUM newlineGUAJAVA L.) INFESTED BY ROOT KNOT NEMATODE, MELOIDOGYNE newlineENTEROLOBII (YANG and EISENBACK, 1983) newlineBy newlineN. ASHOKKUMAR newlineDegree : DOCTOR OF PHILOSOPHY (Agriculture) IN newlinePLANT NEMATOLOGY newlineChairperson : Dr. K. Poornima, Ph.D., newlineProfessor and Head, newlineDepartment of Nematology, newlineAgricultural College and Research Institute, newlineTamil Nadu Agricultural University, newlineCoimbatore - 641 003. newline newline2019 newlineRandom survey was conducted in nine guava growing areas of Tamil Nadu viz., newlineCoimbatore, Erode, Theni, Madurai, Krishnagiri, Dharmapuri, Villupuram, Thiruvannamalai newlineand Dindigul. The results from this survey indicated that the incidence and population of newlinethe guava root knot nematode, Meloidogyne enterolobii was highest in Theni location newline(414/ 200 cc soil and 588 in 5g root) and lowest in Villupuram location (109/200 cc soil newlineand 159 in 5g root). newlineScreening of 15 guava cultivars collected from various districts of Tamil Nadu newlineagainst M.enterolobii revealed five cultivars (Mini guava, Local, White Seedless, Red newlineSeedless and Panneer Guava) to be susceptible and ten others (Alahabad Safeda, newlineLucknow-46, Thailand Red, Banaras, Lucknow-49, Beetroot Guava, Trichy-1, Hisar newlineLalit, Taiwan Guava and Chitidar) to be highly susceptible, based on the root knot gall newlineindex and reproduction factor. newlineMorphological confirmation of females, males, juveniles of M.enterolobii using newlinePosterior Cuticular Pattern (PCP) was done for population obtained from nine districts of newlineTamil Nadu. newlineMolecular confirmation of M.enterolobii females collected from nine districts of newlineTamil Nadu was done by using 28s rRNA. Histopathology of M.enterolobii infested and newlinenon-infested root were done in which the infested roots sections showed complete newlinedisruption of the epidermis, cortex, endodermis, pericycle, xylem and phloem cells, the newlinesections were occupied by clusters of adult females in the cortical region extending their newlineheads into the pericycle (sometimes even upto 60 per gall) and nearly one fourth of the newlinesectioned a