Informatics Publishing Limited

P. S. Shanmugam , R. Seenivasan

Abstract

Eucalyptus vegetative mass production has been advanced through the adoption of many improved methods. The suitability of vegetative mass propagation using minicuttings derived from the minihedges grown in the sand beds was evaluated. The study reveals the superiority of this technique over the regular stem cuttings from the open clonal multiplication area. The minicuttings of Eucalyptus camaldulensis (ITC 413, TNPL 103) and Eucalyptus tereticornis (ITC 3, TNPL 106) clones recorded more than 80% survival in the mist chamber, whereas the stem cuttings from the open CMA of the same clones recorded only 50% survival.The use of growth substances were completely eliminated in the minicuttings.Among the treatment periods T₂(21 days in the mist chamber) proved to be highly effective for the Eucalyptus mass production through the mini cutting method. Except shoot length the other parameters like survival percentage in the mist chamber, 50% shade house, ischolar_main length and number of lateral ischolar_mains was more in T₂ compare to other treatments.The juvenility and nutrient status of the mother plants influences the survival ability of the minicuttings in the mist chamber. The present study reveals the suitability of minicutting clonal production method for E. camaldulensis and E. tereticornis clones in the Indian condition.

Keywords

Minicutting, Minihedge, Juvenility, E. Camaldulensis, E. Tereticornis

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P. S. Shanmugam ¹, R. Balagurunathan ¹, N. Sathiah ¹, N. G. V. Rao ²

Affiliations
1 Department of Agric. Entomology, Tamil Nadu Agricultural University, Coimbatore-641003, Tamil Nadu, IN
2 Department of Biotechnology, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola-444104, Maharashtra, IN

Abstract

The susceptibility of different instars of Earias vittella (Fabrieius) to Bacillus thuringiensis (Bt) insecticidal proteins (ICP) was studied. The LC₅₀ of CrylAa, CrylAb, Cry1Ac, CryiC and Cry1E were 108.54, 97.04, 66.62, 1240.83 and 1335.60 ng/cm², respectively to E. vittella neonates. The order of toxicity of different ICPs to second and third instar was Cry1Ac > CrylAb > CrylAa. Overlap 95 per cent fiducial limits at LC₅₀ of CrylAa and CrylAb showed similar toxicity of these toxins to second and third instars of E. vittella. The possibility of these toxins and toxicity parameters in resistance management is discussed.

Keywords

Bacillus thuringiensis, Earias vittella, Insecticidal Proteins, Median Lethal Concentration, Toxicity.

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