STUDIES ON PLANT RESISTANCE IN FINGER MILLET (Eleusine coracana L.) TO INSECT PEST COMPLEX
| dc.contributor.advisor | Dr. K. V. HARI PRASAD | |
| dc.contributor.author | MANNELA LOKESWARIDEVI | |
| dc.date.accessioned | 2024-03-20T12:30:45Z | |
| dc.date.available | 2024-03-20T12:30:45Z | |
| dc.date.issued | 2024-03-20 | |
| dc.description.abstract | The present investigations on “Studies on plant resistance in finger millet (Eleusine coracana L.) to insect pest complex" was conducted at Agricultural Research Station Perumalapalle, Tirupati; Department of Entomology, S.V. Agricultural College, Tirupati and Institute of Frontier Technology (IFT), RARS, Tirupati during 2021-22. Hundred and four finger millet genotypes were screened to identify the source of resistance to insect pest complex. The major insect that was identified during the period of study, during kharif 2021 and late rabi 2021-22 was ragi pink stem borer Sesamia inferens (Lepidoptera: Noctuidae) and the results pertaining to the same is presented. The reaction of 104 genotypes against pink stem borer incidence in terms of per cent dead hearts, ranged from 8.13 to 67.3 with an average of 15.52 per cent during kharif, 2021. Out of 104 genotypes, 83 genotypes were placed under highly resistant category with <10 per cent dead heart incidence, 12 genotypes under moderately susceptible (10.1 - 40%) and five genotypes (more than 40%) under highly susceptible category to pink stem borer infestation. During late rabi, 2022, the reaction of 104 finger millet genotypes against pink stem borer incidence in terms of per cent dead hearts, ranged from 8.13 to 64.64 with an average of 14.04 per cent. Out of 104 genotypes, 80 genotypes were placed under highly resistant category with <10 per cent dead heart incidence, 15 genotypes under moderately susceptible (10.1 - 40%) and five genotypes under highly susceptible (more than 40%) to pink stem borer infestation. Studies on biophysical characters of resistance revealed that trichome density (- 0.879) and leaf thickness (-0.946) were negatively correlated with mean per cent dead heart incidence. Studies on biochemical characters of resistance revealed that phenols (- 0.825) and chlorophyll content (-0.961) were negatively correlated with mean per cent dead heart incidence, while, total proteins (0.980), amino acids (0.960) and total reducing sugars (0.985) were positively correlated with mean per cent dead heart incidence. Biology studies of Sesamia inferens were done on three selected genotypes, which included IC 0478656 (highly resistant), ER 75 (moderately susceptible) and EN 70 (highly susceptible) from field screening during kharif and late rabi 2021-22. The xiv results indicated that larval duration when the insect was reared on different genotypes of finger millet was minimum on the highly susceptible genotype EN 70 (22.6±0.22days), followed by that on moderately susceptible genotype ER 75 (27.08±0.27), while it was maximum on the highly resistant genotype IC 0478656 (35.2±0.67 days). The mean durations of larval instars of I, II, III, IV, V and VI on highly resistant genotype IC 0478656 were 4.74 ± 0.84, 4.94 ± 1.16, 5.26 ± 0.79, 5.56 ± 1.04, 6.90 ± 0.82 and 7.80 ± 1.19 days, while on highly susceptible genotype EN 70 i.e., it was 3.06 ± 0.89, 3.13 ± 0.62, 3.20 ± 1.24, 4.01 ± 0.47, 4.1 ±0.95, 5.2± 1.08 days. The larval weights when the insect was reared on different genotypes of finger millet were maximum on the highly susceptible genotype EN 70(115.17±2.2 mg), followed by moderately susceptible ER 75 (85.11±1.5 mg) and minimum on the highly resistant genotype IC 0478656 (56.4 ± 1.76 mg). There exists significant difference in larval duration and larval weights when the insect was reared on different genotypes of finger millet. The pupal period, when the insect was reared on different genotypes of finger millet varied from 8-12 days. There exists statistically significant difference in pupal duration and pupal weights when the insect was reared on different genotypes of finger millet. The pupal duration on highly resistant genotype IC 0478656 was 12.3 days, while it was 8.6 days on highly susceptible genotype EN 70. The pupal duration of a moderately susceptible genotype ER 75 was found to be between 8.6 to 12.3 days, i.e., 10.77 days. Similarly, the pupal weight on highly resistant genotype IC 0478656 was 54.4 mg, while it was 73.3 mg on highly susceptible genotype EN 70, whereas the pupal weight on moderately susceptible genotype ER 75 was found to be between 54.5 to 73.3 mg, i.e., 64.18 mg. No significant difference was found with respect to adult longevity, sex ratio when the insect was reared on genotypes with different levels of field resistance. Fecundity of the female moth when the insect was reared from different genotypes of finger millet did not differ significantly however female moth reared on highly susceptible genotype EN 70 laid more eggs (259 eggs) as compared with the resistant genotype IC 0478656 (97 eggs). Incubation period when the insect was reared on different genotypes ranged from 6-7 days, with an average 5.95-days. The total life span of S. inferens, when reared on highly resistant genotype IC 0478656 was 58.5 days, while it was 46.5 days on highly susceptible genotype EN 70. The total life span of a moderately susceptible genotype ER 75 is 51.57 days and these differences were statistically significant. Studies on larval preference indicated that highly susceptible genotype EN 70 was most preferred by the larva of pink stem borer followed by ER 75. Least preferred genotype was highly resistant genotype IC 0478656. Studies on oviposition preference indicated that highly susceptible genotype EN 70 was most preferred by the adult pink stem borer for egg deposition followed by ER 75. Least preferred genotype was highly resistant genotype IC 0478656. | |
| dc.identifier.other | D6532 | |
| dc.identifier.uri | https://krishikosh.egranth.ac.in/handle/1/5810207612 | |
| dc.keywords | PLANT RESISTANCE | |
| dc.keywords | FINGER MILLET | |
| dc.language.iso | English | |
| dc.pages | 135 | |
| dc.publisher | Acharya N G Ranga Agricultural University | |
| dc.relation.ispartofseries | D6532; D6532 | |
| dc.sub | Entomology | |
| dc.theme | STUDIES ON PLANT RESISTANCE IN FINGER MILLET (Eleusine coracana L.) TO INSECT PEST COMPLEX | |
| dc.these.type | M.Sc | |
| dc.title | STUDIES ON PLANT RESISTANCE IN FINGER MILLET (Eleusine coracana L.) TO INSECT PEST COMPLEX | |
| dc.type | Thesis |