Sesame ( Sesamum indicum Linn.) (Pedaliaceae) is an important oilseed crop grown in many countries. Among the insect pests infesting sesame, the webworm, Antigastra catalaunalis Duponchel (Pyraustidae: Lepidoptera) is predominant throughout the crop period. For managing this insect, resistant sesame varieties with higher yield potential and better adaptability to varied locations are essentially needed. Keeping this in view and based on earlier work, three promising accessions viz., IVTS-2001-7, KMR-102 and TMV-3 were selected. To enhance resistance and/or yield traits, these three accessions in comparison with a susceptible check SVPR 1 were subjected to mutagenesis using gamma rays as physical mutagen; Ethyl Methane Sulphonate (EMS) and Diethyl Sulphate (DES) as chemical mutants. The first and generation mutants were evaluated under field conditions at Methikudi village, Cuddalore district, Tamil Nadu, Southern India during May, 2012-September, 2014. Webworm infestation was evaluated based on leaf, flower and capsule damage. Among the first mutant (M 1) and second mutant (M 2) generations, plants of the accessions namely IVTS 2001-7 and TMV-3 were rated as resistant and plants of SVPR-1 were highly susceptible to A. catalaunalis.
Sesame (Sesamum indicum Linn.) (Pedaliaceae) is an important oilseed crop grown widely in India and other countries. In most of the countries including India, sesame is an underutilized crop of local importance, which warrants improved use and conservation. In many countries, it is being cultivated under both rainfed and irrigated conditions. Among the sesame cultivating countries, though India ranks first in the production, the productivity is comparatively less (413 kg/ha). This shortfall in the productivity is attributed to the incidence of insect pests. Among the key insect pests, webworm, Antigastra catalaunalis (Duponchel) (Pyraustidae: Lepidoptera) is the most serious. It occurs regularly and infests the crop during seedling, flowering and maturity stages and causes up to 90% yield loss [
Three sesame accessions viz., IVTS-2001-7, KMR-102 and TMV-3 found promising against webworm were selected and in this study, they were subjected to physical and chemical mutagenesis. The mutant generations were evaluated for insect resistance in terms of leaf, flower and capsule damage and also yield.
Physical mutagen namely gamma rays and chemical mutagens namely Ethyl Methane Sulphonate (EMS) and Diethyl Sulphate (DES) were employed for treating the seeds of the selected accessions. Before mutagenesis, the LD50 values for each mutagen were determined by recording the seed germination in various dosages. Hundred seeds were placed on moist germination paper, replicated twice, for estimating the germination percentage and seedling vigour. For each accession, 500 well filled seeds were irradiated with gamma rays at specified dose determined based on the LD50 value reported earlier for this crop. Gamma radiation of the seeds was done at Centre for Application of Radioisotopes & Radiation Technology (CARRT), Mangalore University, Mangalore, India. For chemical mutagenesis, seeds pre-soaked in distilled water were treated with EMS for three hours. For DES, the mutagenic solution was changed once in half-an- hour by adding freshly prepared solution, as the half-life of the chemical is one hour at 30˚C. Non-irradiated dry seeds and seeds pre-soaked in distilled water served as the control.
The seeds subjected to mutagenesis were sown in the field along with the untreated parents under randomized block design with necessary replications. For each mutant generation, 30 plants per replication were raised and evaluated.
Field screening of sesame accessions was done at the Methikudi village, Cuddalore district, Tamil Nadu, Southern India (latitude 11.39˚N and longitude 79.71˚E), during May, 2012-September, 2014. The sesame accessions were sown on the ridges of two metre length with a spacing of 30 cm between rows and 30 cm between plants. Thirty plants per replication and three replications were maintained per accession. A known susceptible check namely SVPR-1 [
The data obtained from the field screening of selected sesame accessions were analysed as per the standard methods [
In M1 generation, among the three accessions, the minimum leaf damage was observed in IVTS 2001-7 in DES mutation followed by DES induced mutants of TMV-3 (
In M1 generation, the lowest flower damage was observed in plants of IVTS 2001-7 mutagenized with EMS (
Regarding capsule damage, EMS induced mutants of TMV-3 registered the minimum capsule damage in the first generation. The maximum capsule damage was noticed in DES induced mutants of SVPR-1 (
Genotypes | Control | Gamma ray 50 Krad | EMS 0.5% | DES 0.06% | ||||
---|---|---|---|---|---|---|---|---|
% leaf damage | CV | % leaf damage | CV | % leaf damage | CV | % leaf damage | CV | |
IVTS 2001-7 | 1.90 ± 0.11 (7.92 ± 0.05) | 2.46 (1.21) | 1.40 ± 0.02 (6.80 ± 0.04) | 3.13 (1.25) | 1.90 ± 0.12 (7.92 ± 0.09) | 4.18 (2.10) | 1.31 ± 0.06 (6.60 ± 0.18) | 9.08 (4.76) |
KMR 102 | 4.91 ± 0.05 (12.80 ± 0.17) | 4.12 (2.42) | 6.41 ± 0.16 (14.69 ± 0.04) | 4.21 (2.14) | 5.30 ± 0.02 (13.31 ± 0.09) | 2.05 (1.17) | 4.69 ± 0.08 (12.51 ± 0.11) | 2.88 (1.57) |
TMV-3 | 2.63 ± 0.11 (9.32 ± 0.13) | 4.84 (2.56) | 2.09 ± 0.04 (8.33 ± 0.04) | 3.05 (1.67) | 3.33 ± 0.06 (10.51 ± 0.20) | 5.71 (3.29) | 3.70 ± 0.02 (11.09 ± 0.05) | 1.39 (0.78) |
SVPR-1 | 12.89 ± 0.28 (21.04 ± 0.32) | 4.98 (2.65) | 13.11 ± 0.27 (21.24 ± 0.04) | 3.65 (1.91) | 18.68 ± 0.16 (25.62 ± 0.03) | 1.75 (0.49) | 10.87 ± 0.35 (25.63 ± 0.11) | 3.62 (1.92) |
S. Ed. | 0.05 | 0.07 | 0.06 | 0.08 | ||||
C. D. (p = 0.05) | 0.10 | 0.14 | 0.12 | 0.18 |
Each value is a mean of three replications @ thirty plants/replication; Values in parentheses are arc sine transformed values.
Genotypes | Control | Gamma ray 50 Krad | EMS 0.5% | DES 0.06% | ||||
---|---|---|---|---|---|---|---|---|
% flower damage | CV | % flower damage | CV | % flower damage | CV | % flower damage | CV | |
IVTS 2001-7 | 1.40 ± 0.04 (6.80 ± 0.05) | 2.12 (1.16) | 1.80 ± 0.02 (7.72 ± 0.05) | 1.91 (1.01) | 2.01 ± 0.04 (8.14 ± 0.06) | 7.10 (3.85) | 0.07 ± 0.05 (4.76 ± 0.20) | 14.17 (7.15) |
KMR 102 | 3.12 ± 0.07 (10.19 ± 0.10) | 2.83 (1.70) | 2.82 ± 0.04 (9.81 ± 0.06) | 2.09 (1.03) | 2.71 ± 0.07 (9.46 ± 0.10) | 2.94 (1.88) | 4.41 ± 0.08 (12.12 ± 0.11) | 2.99 (1.63) |
TMV-3 | 1.90 ± 0.05 (7.93 ± 0.07) | 3.30 (1.68) | 0.79 ± 0.03 (5.10 ± 0.10) | 6.56 (3.32) | 1.50 ± 0.04 (7.05 ± 0.09) | 4.66 (2.45) | 1.55 ± 0.05 (7.19 ± 0.10) | 5.61 (2.60) |
SVPR-1 | 11.20 ± 0.14 (19.56 ± 0.09) | 1.36 (0.75) | 9.60 ± 0.02 (18.05 ± 0.03) | 0.44 (0.25) | 7.33 ± 0.16 (15.70 ± 0.06) | 2.48 (1.25) | 6.40 ± 0.09 (14.65 ± 0.11) | 2.30 (1.32) |
S. Ed. | 0.04 | 0.09 | 0.08 | 0.07 | ||||
C. D. (p = 0.05) | 0.08 | 0.20 | 0.18 | 0.15 |
Each value is a mean of three replications @ thirty plants/replication; Values in parentheses are arc sine transformed values.
Genotypes | Control | Gamma ray 50 Krad | EMS 0.5% | DES 0.06% | ||||
---|---|---|---|---|---|---|---|---|
% capsule damage | CV | % capsule damage | CV | % capsule damage | CV | % capsule damage | CV | |
IVTS 2001-7 | 1.71 0.05 (7.51 ± 0.96) | (2.65 (1.16) | 1.01 ± 0.06 (5.81 ± 0.17) | 4.2 (2.45) | 0.70 ± 0.04 (5.72 ± 0.20) | 26..34 (3.06) | 1.31 ± 0.03 (5.66 ± 0.04) | 14.17 (7.14) |
KMR 102 | 3.32 ± 0.03 (10.49 ± 0.20) | 7.85 (4.21) | 1.80 ± 0.05 (7.71 ± 0.12) | 11.23 (5.94) | 2.39 ± 0.03 (8.89 ± 0.15) | 5.88 (3.05) | 4.69 ± 0.06 (7.71 ± 0.04) | 4.01 (2.33) |
TMV-3 | 1.80 ± 2.04 (7.72 ± 0.04) | 2.48 (1.68) | 1.30 ± 0.02 (6.55 ± 0.05) | 6.00 (2.95) | 1.00 ± 0.06 (5.72 ± 0.20) | 36.04 (13.66) | 3.70 ± 0.05 (7.92 ± 0.04) | 5.61 (2.60) |
SVPR-1 | 6.87 ± 0.05 (15.18 ± 0.11) | 1.45 (0.75) | 7.31 ± 0.05 (6.59 ± 0.05) | 4.52 (2.18) | 8.01± 0.05 (16.45 ± 0.04) | 3.23 (1.70) | 16.87 ± 0.05 (17.92 ± 0.04) | 2.30 (1.32) |
S. Ed. | 0.05 | 0.03 | 0.09 | 0.07 | ||||
C. D. (p = 0.05) | 0.10 | 0.06 | 0.18 | 0.15 |
Each value is a mean of three replications @ thirty plants/replication; Values in parentheses are arc sine transformed values.
Among the two mutagenesis methods, chemical mutants performed better than the physical mutants. Among the mutant generations, DES induced mutants of IVTS 2001- 7 showed the minimum leaf damage in both the generations. Flower damage was the least in EMS induced mutants of IVTS 2001-7 in the M1 generation, while in the M2 generation, DES induced mutants were better. In contrast to the above, capsule damage was the least in EMS induced mutants of TMV-3 in the M1 and M2 generations. This trend clearly indicates the segregation of the traits. Webworm resistance traits were found promising in the mutants of IVTS 2001-7 and TMV-3. But mutant plants of KMR-102 registered the maximum yield. In some of the mutants plants of KMR-102, desirable yield enhancing characters such as tripodding in a single node were observed, as reported earlier [
Hence it is concluded that mutant plants of IVTS 2001-7 and TMV-3 may be evaluated and exploited in the further generations for insect resistant traits while mutants of KMR-102 may be used as yield contributing donor in future breeding programme.
The authors are thankful to Department of Science and Technology, Government of India for the financial support and Annamalai University for providing necessary facilities for carrying out this study.
Saravanaraman, M., Selvanarayanan, V. and Saravanan, K. (2017) Reaction of Sesame (Sesamum indicum Linn.) Mutant Generations against Webworm, Antigastra catalaunalis Duponchel. Advances in Entomology, 5, 26-32. http://dx.doi.org/10.4236/ae.2017.51002