Indian Journal of Agricultural Research

  • Chief EditorV. Geethalakshmi

  • Print ISSN 0367-8245

  • Online ISSN 0976-058X

  • NAAS Rating 5.60

  • SJR 0.293

Frequency :
Bi-monthly (February, April, June, August, October and December)
Indexing Services :
BIOSIS Preview, ISI Citation Index, Biological Abstracts, Elsevier (Scopus and Embase), AGRICOLA, Google Scholar, CrossRef, CAB Abstracting Journals, Chemical Abstracts, Indian Science Abstracts, EBSCO Indexing Services, Index Copernicus
Indian Journal of Agricultural Research, volume 57 issue 4 (august 2023) : 543-547

Effect of Alternaria sesami on Germination and Seedling Growth of Sesame

P. Lakshmi Pravallika1,*, S.L. Bhattiprolu1, K. Radhika1, M. Raghavendra1
1Regional Agricultural Research Station, Acharya N.G. Ranga Agricultural University, Lam, Guntur-522 034, Andhra Pradesh, India.
Cite article:- Pravallika Lakshmi P., Bhattiprolu S.L., Radhika K., Raghavendra M. (2023). Effect of Alternaria sesami on Germination and Seedling Growth of Sesame . Indian Journal of Agricultural Research. 57(4): 543-547. doi: 10.18805/IJARe.A-5601.
Background: Sesame is an important oil seed crop affected by toxigenic fungal pathogens viz., Alternaria, Fusarium and Aspergillus. Among these, Alternaria sesami is seed borne and most destructive pathogen causing yield loss to an extent of 28.9 per cent. Hence the effect of artificial infection with A. sesami on seed quality of various samples of sesame was investigated during 2017-2018. 

Methods: A total of 28 samples were collected from different sesame growing areas of Andhra Pradesh and Telangana and inoculated with A. sesami. The inoculated and uninoculated seeds were tested for germination and seedling growth by rolled paper towel method.

Result: Significant differences in seed germination, seedling length and seedling vigour index were observed among the uninoculated as well as inoculated sesame seed samples. The results indicated that Alternaria sesami caused 15.13% to 49.68%, 12.77% to 46.14% and 28.28% to 72.87% reduction in seed germination, seedling length and vigour index, respectively, of inoculated seed over uninoculated seeds. The per cent reduction was highest in the seed samples of YLM-17 collected from farmers’ saved seed samples of Prakasam district.
Sesame (Sesamum indicum L.) is an ancient oil yielding crop in the world and known as “Queen of Oilseeds” due to high cooking quality and medicinal value (Tiwari et al., 2011). Presence of potent antioxidants (sesamolin and sesamol) makes sesame oil to be one of the most stable oils in the world. It is cultivated mainly for its high quality edible oil as the seed contains more than 50% oil with a balanced composition of oleic and linoleic acid and it is also used as a flavoring agent. Besides food, sesame is used as an active ingredient in antiseptics, bactericides, viricides, disinfectants, moth repellants and antitubercular agents (Bedigian et al., 1985).

Seed borne microflora are carried over by infected seed and cause seed deterioration, reduce germination, vigour and weaken the initial seedling growth resulting in the reduction of plant population in the field. Sesame plants are highly susceptible to fungal infections, including toxin-producing fungi. Among the several toxigenic fungi, the predominant fungi are Alternaria, Fusarium and Aspergillus. Post-harvest conditions favour infection during storage which may lead to production of different mycotoxins. These toxigenic fungal pathogens are important constraints to the production of the crop, affecting the seed quality parameters like germination, seedling vigour and also biochemical properties during storage. So, there is a need to study the effect of seed-borne fungal pathogens on seed quality parameters of sesame.
The present investigation was carried out in the laboratory of Plant Pathology, Regional Agricultural Research Station, Lam and the Department of Seed Science and Technology, Advanced Post Graduate Centre, Lam, Guntur, Andhra Pradesh during 2017-2018. A total of 28 samples were collected from different sesame growing areas viz., five samples from Agricultural Research Station (ARS), Yellamanchili; four samples from Regional Agricultural Research Station (RARS), Lam, Guntur; 16 farmers’ saved samples from villages of Darsi and Marturu mandals of Prakasam district of Andhra Pradesh and three samples from RARS, Jagtial, Telangana.
 
Preparation of Culture Filtrate
 
A small disc of 5 mm diameter was cut from the margin of actively growing 3-day old fungal colony with the help of a sterile cork borer and the fungal disc was transferred aseptically into a 100 ml flask containing 20 ml of sterile broth. The flasks were incubated at 28±1°C for 15 days. At the end of incubation, when the growth was full, the fungal mats were filtered repeatedly through a double layer of Whatman No. 41 filter papers. From the filtrate obtained, the conidia were adjusted to required concentration (106 conidia/ ml) by using a haemocytometer and the density of original suspension in number of cells/ml was calculated by multiplying with dilution factor as given by Karuna Vishunavat and Kolte (2005).
 
 
Seed Inoculation
 
Apparently healthy seed of sesame cultivars were surface sterilized. The sterilized seeds were soaked in conidial suspension of A. sesami for 30 min and dried at room temperature overnight. The seeds of control treatments were similarly treated except that they were soaked in sterile distilled water.
 
Evaluation of Seed Quality
 
The inoculated seeds and control (uninoculated) seeds were kept for germination between moistened paper towels using rolled paper method. Four replications of 100 seed from each seed sample were placed on the germination paper at uniform spacing. The paper towels were rolled, lined with blotter paper and placed in plastic tray in an upright position at ambient conditions for six days.
 
Observations Recorded
 
Observations on various seed quality parameters viz., germination (%) and seedling length (cm) were recorded as detailed below
 
Germination (%)
 
On the day of final count (6th day), all the normal seedlings were counted. Based on the number of normal seedlings, the germination percentage from each sample in each replication was computed using the formula:
 
 
                                                               
Seedling Length (cm)
 
Ten normal seedlings, at random, were taken from each replication of samples on the 6th day and the seedling length was measured from the tip of the primary leaf to the tip of the primary root with the help of the scale and mean seedling length was expressed in centimetres.
 
Seedling Vigour Index
 
Seedling vigour index was computed using the following formula given by Abdul-Baki and Anderson (1973).
  
 
 Statistical Analysis
 
The data recorded as percentage was subjected to angular (arc sin) transformation before statistical analysis. The standard method of analysis of variance technique appropriate to the Completely Randomized Design (CRD) as described by Panse and Sukhatma (1985) was used. The data were analyzed by employing ‘paired t test’ at five per cent level of significance on the basis of null hypothesis using SPSS software. The appropriate standard error of mean (S.Em. ±) were calculated in each case and the Standard Deviation (S.D.) at five per cent level of probability were worked out to compare the two treatment means, where the treatment effects were found significant under ‘paired t’ test.
 
The inhibitory effect of major seed-borne fungus, Alternaria sesami was observed on seed germination, seedling length and seedling vigour index of sesame seed samples collected from different locations (Table 1).

Table 1: Effect of major seed borne fungus, Alternaria sesami on germination, seedling length and seedling vigour of sesame.


 
Germination (%)
 
Significant variation in germination was observed between the inoculated and uninoculated sesame seed samples collected from different areas of Andhra Pradesh and Telangana (Table 1). The uninoculated seed samples exhibited 92.00% to 98.25% germination, while the inoculated seed samples showed germination ranging from 49.06% to 83.38% irrespective of locations and sources. The germination was inhibited by Alternaria sesami in all the seed samples.
 
Maximum reduction (49.68%) in germination of inoculated seed over uninoculated sample was observed in the farmers’ saved seed sample no. 14 followed by farmers’ sample no. 15 (47.12%) of YLM-17, whereas the least reduction (15.13%) was observed in foundation seed sample of YLM-66 collected from ARS, Yellamanchili (Fig 1). Sesame seed samples collected from different locations showed that maximum per cent reduction in germination of inoculated seed over uninoculated seed was observed with samples collected from farmers’ of Darsi and Maruturu mandals of Prakasam district with the range of 30.31% to 49.68% followed by seed samples from RARS, Lam, Guntur (15.90% to 23.81%). The samples collected from ARS, Yellamanchili showed the least per cent reduction of germination ranging from 15.13% to 21.40%, while samples from RARS, Jagitial recorded 17.51% to 21.53% reduction in germination.

Fig 1: Effect of Alternaria sesami on germination, seedling length and vigour index in sesame.


 
Seedling Length (cm)
 
Seedling length was found to vary significantly between the inoculated and uninoculated sesame seed samples collected from different locations of Andhra Pradesh and Telangana (Table 1). The seedling length varied from 9.12 cm to 14.96 cm in uninoculated and 5.30 cm to 11.70 cm in inoculated seed samples across different locations and sources of sample collection.

The seedling length decreased after artificial inoculation in all the seed samples. Among the 28 samples, maximum reduction in seedling length (46.14%) was observed in the farmers’ sample no. 14 of YLM-17, whereas the least reduction (12.77%) was observed in foundation seed sample of Swetha (sample no. 27) collected from RARS, Jagitial (Fig 1). maximum per cent reduction was observed with samples collected from farmers’ of Darsi and Maruturu mandals of Prakasam district with a range of 21.77% to 46.14% followed by seed samples from RARS, Lam, Guntur (18.31% to 29.59%). The samples collected from RARS, Jagitial and ARS, Yellamanchili exhibited reduction in seedling length to the tune of 12.77% to 19.75%.
 
Seedling Vigour Index
 
Inoculated and uninoculated sesame seed samples collected from different areas of Andhra Pradesh and Telangana showed significant variation in seedling vigour index. The range of seedling vigour index of uninoculated and inoculated seed samples of sesame was 839 to 1456 and 323 to 964, respectively (Table 1).

Reduction in seedling vigour index, after inoculation with Alternaria sesami, was observed in all the seed samples of sesame. Maximum reduction in seedling vigour index of inoculated sample over uninoculated sample (72.87%) was observed in the farmers’ sample no. 14 followed by farmers’ sample no. 15 (68.42%) of YLM-17, whereas the least reduction (28.28%) was observed in foundation seed sample of Swetha (sample no. 27) collected from RARS, Jagitial (Fig 1). In sesame seed samples, maximum per cent reduction was observed with samples collected from farmers’ of Darsi and Maruturu mandals of Prakasam district with the range of 45.57% to 72.87% followed by seed samples from RARS, Lam, Guntur (31.30% to 46.33%). The samples collected from RARS, Jagitial showed the least per cent reduction of seedling vigour index ranging from 28.28% to 35.83%, while samples from ARS, Yellamanchili recorded 29.38% to 38.41% reduction in seedling vigour index of uninoculated sample over inoculated sample.

Decreased germination, seedling length and seedling vigour index were observed in seed samples of Prakasam district with an increased total number of fungal colonies. Sesame seed samples with the highest fungal flora also recorded less germination, seedling length and seedling vigour. The reduction in germination may be due to the usage of energy rich compounds by these fungi that are otherwise required for proper germination (Irshad et al., 2017). This effect may be due to seed-borne fungi like Alternaria, which is known to produce some toxins that are detrimental to seed germination (Ramegowda and Naik, 2008). Alternaria species produce non-host specific toxins [e.g., tenuazonic acid (TeA), alternariol (AOH), alternariol monomethyl ether (AME), brefeldin A, tentoxin and zinniol] (Saha et al., 2012) as well as host-specific toxins (Thomma, 2003) which contaminate the seed. Rao and Vijayalakshmi (2000) reported tenuazonic acid (TA) toxin production by Alternaria sesami in sesame resulting in reduced germination and seedling vigour.

Similar variation in reduction of germination (%), seedling length (cm) and seedling vigour index of uninoculated seed over inoculated seed was earlier reported by Bavaji et al., (2000); Naik et al., (2017) and Nayyar et al., (2017) in sesame. Ahammed et al., (2006) in soybean, Anand et al., (2008) in groundnut, Kumar (2010) in finger millet, Bhajbhuje (2015) in wheat and Chaudhari et al., (2017) in redgram reported that seed borne fungi reduced the germination, seedling vigour and other seed quality parameters.

Hence, from the results it is concluded that seed borne fungus, Alternaria sesami inhibits the seed germination, seedling length and vigour of sesame seedlings to a great extent. Hence, farmers’ are advised to take preventive measures including selection of sesame seed from healthy fields followed by treating the seeds with recommended fungicides to achieve good germination, initial vigour and optimum plant population in the field for realizing higher yields.

  1. Abdul-Baki, A.A. and Anderson, J.D. (1973). Vigor determination in soybean seed by multiple criteria. Crop Science. 13(6): 630-633.

  2. Ahammed, S.K., Anandam, R., Babu, G.P., Munikrishnaiah, M. and Gopal, K. (2006). Studies on seed mycoflora of soybean and its effect on seed and seedling quality characters. Legume Research-An International Journal. 29:186-190.

  3. Anand, T., Bhaskaran, R., Karthikeyan, T.G., Rajesh, M. and Senthilraja, G. (2008). Production of cell wall degrading enzymes and toxins by Colletotrichum capsici and Alternaria alternata causing fruit rot of chillies. Journal of Plant Protection Research. 48: 437-451.

  4. Bavaji, M., Latheef, S. and Sreeramulu, A. (2000). Effect of Alternaria alternata culture filtrate on seed germination and seedling growth of Sesamum indicum L. Journal of Ecotoxicology and Environmental Monitoring. 10: 215-216.

  5. Bedigian, D., Seigler, D.S. and Harlan, J.R. (1985). Sesamin, sesamolin and the origin of sesame. Biochemical Systematics and Ecology. 13: 133-139.

  6. Bhajbhuje, M.N. (2015). Response of metabolites from culture filtrates of Alternaria species against Triticum aestivum L. International Journal of Life Sciences. 3: 55-62.

  7. Chaudhari, A., Sharma, H., Jehani, M. and Sharma, J.K. (2017). Seed mycoflora associated with pigeonpea [Cajanus cajan (L.) Millsp.] their significance and the management. Journal of Pure and Applied Microbiology. 11(1): 567-575.

  8. Irshad, G., Gazal, H., Naz, F., Hassan, I., Bashir, A. and Ghuffar, S. (2017). Detection and in vitro management of seed borne mycoflora associated with sunflower and zinnia. Pakistan Journal of Phytopathology. 29: 07-16.

  9. Karuna, Vishunavat and Kolte, S.J. (2005). Essentials of phytopathological techniques. Kalyani Publishers, New Delhi. pp. 25-26.

  10. Kumar, B. (2010). Phytotoxic effect of seed mycoflora associated with the genotypes of finger millet (Eleusine coracana). Progressive Agriculture. An International journal. 10: 112-115.

  11. Naik, M., Chennappa, G., Amaresh, Y., Sudha, S., Chowdappa, P. and Patil, S. (2017). Characterization of phytotoxin producing Alternaria species isolated from sesame leaves and their toxicity. Indian Journal of Experimental Biology. 55: 36-43.

  12. Nayyar, B.G., Woodward. S., Mur, L.A., Akram, A., Arshad, M., Naqvi, S.S. and Akhund, S. (2017). The incidence of Alternaria species associated with infected (Sesamum indicum L.) seeds from fields of the Punjab, Pakistan. The Plant Pathology Journal. 33: 543.

  13. Panse, V.G. and Sukhatme, P.V. (1954). Statistical methods for agricultural workers. ICAR, New Delhi. pp.152-155.

  14. Ramegowda, G. and Naik, M. (2008). Toxigenic diversity of Alternaria spp. infecting Bt-cotton and induction of systemic resistance to Alternaria leaf spot. Journal of Mycopathological Research. 46: 221-226.

  15. Rao, N.R. and Vijayalakshmi, M. (2000). Studies on Alternaria sesami pathogenic to sesame. Microbiological Research. 155: 129-131.

  16. Saha, Debjani, Ramona, F., Britta, B., Joachim, P., Manfred, M., Ha, D., Christopher, L. and Reinhard, F. (2012). Identification of a polyketide synthase required for alternariol (AOH) and alternariol-9-methyl ether (AME) formation in Alternaria alternata. PLoS One. 7(7): 540-564.

  17. Thomma, B.P. (2003). Alternaria spp. From general saprophyte to specific parasite. Molecular Plant Pathology. 4: 225-236.

  18. Tiwari, S., Kumar, S. and Gontia, I. (2011). Biotechnological approaches for sesame (Sesamum indicum L.) and Niger (Guizotia abyssinica Lf Cass.). Asia-Pacific Journal of Molecular Biology and Biotechnology. 19: 2-9.

Editorial Board

View all (0)