International Journal of Pure & Applied Bioscience (IJPAB)
Year : 2017, Volume : 5, Issue : 6
First page : (1528) Last page : (1537)
Article doi: http://dx.doi.org/10.18782/2320-7051.5525
Variability Among the Isolates of Sarocladium Oryzae Incitant of Rice Sheath Rot
Y. Sunil Kumar* and A. K. Patibanda
Department of Plant Pathology, Acharya N.G. Ranga Agricultural University,
S. V. Agricultural College, Tirupati, Andhra Pradesh, India
*Corresponding Author E-mail: ysunilkumar5790@gmail.com
Received: 24.08.2017 | Revised: 29.09.2017 | Accepted: 3.10.2017
ABSTRACT
Ten sympatric isolates were collected, five from each of the two districts and assessed for the variability in radial growth, length of conidia, length of conidiophore and conidiation was observed on five different media. Variability was also assessed on pathogenic potential (disease causing ability) of all the 10 isolates using detached leaf technique by inoculating 20 day old 5mm culture disc. RLEA and PDA were the best solid media utilized by S. oryzae as carbon source. Isolate So DVS had least growth (1.2cm) while isolate So SKL (1.7cm) and So PTR (1.7cm) had maximum radial growth. RLEB was the best liquid medium utilized by S. oryzae (0.82g). Least mycelial dry weight was observed on OMB (0.25g), PDB (0.28g), CDB (0.3g) and PSB (0.3g). Isolate So SKL showed highest dry weight of mycelial mat 0.55g followed by So PTR (0.5g). Isolate So RCP recorded least growth of 0.2g. Among the isolates, maximum dry weight was observed in So SKL on RLEB (1.45g) while the least mycelial dry weight was observed in So RCP (0.04g). The conidiation was highest with isolate So IDP (68.6 X 106/sq cm) while it was least with isolate So SKL (24.7 X 106/sq cm). Among the media, isolates of S. oryzae utilized OMA (49.2 X 106/sq cm) as the best source for conidiation followed by CDA (46.2 X 106/sq cm). Conidiation was least on RLEA (22.3 X 106/sq cm). Isolate So IDP recorded highest conidiation (174.24 X 106/sq cm) on CDA while least was recorded with So PLK (6.4 X 106/sq cm) on CDA. Over all the media tested maximum mean length of conidiophore was recorded in isolate So RCP (101.2µm) while the least length of conidiophore was recorded in isolate So IDP (66.6µm). Over all the isolates tested maximum length of conidiophore was recorded on RLEA (95.5µm) while least length of conidiophore was recorded on PSA (81.2µm). Among the different isolates tested isolate So PLK recorded longest length of conidiophore (156.9µm) on RLEA while smallest conidiophore length was recorded in So SKL (42.0µm). Over all the media isolate So DVS (9.3µm) recorded longest conidia while So VMP (5.9µm) recorded least conidia length. Over all isolates tested, highest length of conidia was recorded on CDA (8.6µm) while least length of conidia was recorded in RLEA (5.9µm). Longest length was observed in isolate So DVS on CDA (13.6µm) while the least conidial length was observed in So SKL (4.0µm). The pathogen could cause disease only on boot leaf sheath but not on lower leaf sheaths of the culm when detached leaf technique using culture disc placement method was followed on cultivar NLR 3041. Isolate So NDP gave maximum lesion length of 1.5cm in nine days after inoculation. While So PTR gave the least lesion length measuring 0.6cm. Isolate So RCP failed to show any symptoms in vitro indicating possibility of availability of resistance among rice genotypes.
Key words: Isolates, Sarocladium oryzae (So), radial growth, mycelial dry weight, conidiophoreFull Text : PDF; Journal doi : http://dx.doi.org/10.18782
Cite this article: Kumar, Y.S. and Patibanda, A.K., Variability Among the Isolates of Sarocladium Oryzae Incitant of Rice Sheath Rot, Int. J. Pure App. Biosci.5(6): 1528-1537 (2017). doi: http://dx.doi.org/10.18782/2320-7051.5525
