Distribution of micro-fungal propagules in storage on seeds of Lycopersicon esculentum Mill

Abstract

Seed is a symbol and foundation of life as it is a container of embryos of a new generation and vehicle
for the spread of new life. The high level seed moisture content, relative humidity and suitable
temperature support the fungal microbes to contaminate essential seed components causing multifold
losses. A total of twenty seed samples of five cultivars of Lycopersicon esculentum Mill. obtained
from various locations of Central India (Vidarbha), were mycologicaly analyzed by standard seed
health testing technique revealed the prevalence of 49 diverse fungal species belonging to 29 genera
from mixed seed samples, with higher count of species and percent incidence for Fusarium and
Aspergillus followed by Curvularia (55%), Alternaria (42%) Rhizoctonia (33%) while others had
moderate to low incidence. Deuteromycota contributed highest, 46.9% fungal count followed
Ascomycota (38.9%); Zygomycota and Oomycota (6.1%). A least count was recorded with
Basidiomycota. Aspergillus nidulans, A. sulphureus, A. ochracious, A. amstelodomi, Fusarium
moniliformae, F. semitectum, Geotrichum candidus, Paecilomyces varioti, Penicillium oxalicum and
Sporotrichum pulverulentum have been recorded on tomato seeds for the first time in India.
Deuteromycota contributed more than half, 52.1% incidence followed by Ascomycota (35.1%);
Zygomycota (5.9%) and Oomycota (5.2%) while Basidiomycota contributed little incidence. A total of
28 to 36 isolates belongs to 19 to 23 genera were confined to individual cultivar seeds. Alternaria
porri, A. solani, Aspergillus flavus, A. fumigatus, A. niger, Botrytis cinera, Cladosporium tenuissium,
Colletotrichum dematium, Curvularia lunata, Didymella lycopersici, Fusarium moniliformae, F.
lycopersici and Phytophthora infestans were appeared to be common on seeds of all cultivars as
external and internal seed borne pathogens. Drachslera rostrata, Fusarium culmorum, F. equiseti,
Rhizopus stolonifer, Rhizoctonia solani were confined to blotter paper while Chaetomium globosum,
Curvularia ovoides, Fusarium solani, Geotrichum candidum were restricted to agar plating. Greatest
count of fungal isolates and percent incidence was recorded by blotter test against agar plating. The
standard blotter technique proved superior over agar plating.