ABSTRACT
Aim: The study aims to develop an advanced non-destructive method to estimate the plant growth rate of tissue culture propagated banana plantlets during primary hardening phase inside the greenhouse using Bootstrapped Artificial Neural Network (BANN). Methodology: Both non-destructive growth parameters like plant height, girth, number of leaves, leaf length and leaf breadth, and destructive growth parameters like number of roots, longest root length, fresh and dry weight were measured periodically on selected plants of one week to nine week old which were kept in greenhouse at ICAR-National Research Centre for banana. In addition to plant growth parameters, greenhouse temperature, radiation and carbon dioxide concentration were also recorded daily. The experimental data obtained using destructive measurements were recorded on a small sample of size n, and hence re-sampling for bootstrap involves n repeated trials of simple random sampling with replacement. These sets of bootstrap samples were finally used as input to develop neural model using a novel methodology of bootstrap re-sampling based artificial neural network (ANN) for studying the progress of plant ontogeny. Results: The growth estimation analysis of plants in terms of its leaf area and biomass production was performed without physically handling the test plants using bootstrap ANN. The notion of prediction performance is validated through statistical indices namely Nash and Sutcliffe efficiency coefficient, root means square error and mean absolute error. The approximate estimates of mean relative growth and net assimilation rate of plants were 0.036 and 0.027, and the corresponding variance were 1.5 x 10-6 and 2.12 x 10-6, respectively. Interpretation: Based on the non-destructive plant growth observations, the measures to increase the overall plant growth can be significantly predicted well in advance. This projected plant growth statistics at an early stage of hardening serves as an essential component in planning and evaluation of investments on protected structure to improve the productivity and profitability of banana tissue culture industry.
ABSTRACT
Shoot tips and in vitro grown proliferating buds of banana cv. Rasthali (Silk, AAB) were treated with various concentrations and durations of chemical mutagens viz., EMS, NaN3 and DES. LD50 for shoot tips based on 50% reduction in fresh weight was determined as 2% for 3 h, 0.02% for 5 h and 0.15%for 5 h, while for proliferating buds, they were 0.6% for 30 min, 0.01% for 2 h and 0.06% for 2 h for the mutagens EMS, NaN3 and DES, respectively. Subsequently, the mutated explants were screened in vitro against fusarium wilt using selection agents like fusaric acid and culture filtrate. LD50 for in vitro selection agents calculated based on 50% survival of explants was 0.050 mM and 7% for fusaric acid and culture filtrate, respectively and beyond which a rapid decline in growth was observed. This was followed by pot screening which led to the identification of three putative resistant mutants with an internal disease score of 1 (corm completely clean, no vascular discolouration). The putative mutants identified in the present study have also been mass multiplied in vitro.
ABSTRACT
The viral genome-linked protein (VPg) of Potyviruses is covalently attached to the 5’ end of the genomic RNA. Towards biophysical characterization, the VPg coding region of Cardamom mosaic virus (CdMV) was amplified from the cDNA and expressed in E. coli. Most of the expressed VPg aggregated as inclusion bodies that were solubilized with urea and refolded with L-arginine hydrochloride. The various forms of CdMV VPg (native, denatured and refolded) were purified and the conformational variations between these forms were observed with fluorescence spectroscopy. Native and refolded CdMV VPg showed unordered secondary structure in the circular dichroism (CD) spectrum. The model of CdMV VPg was built based on the crystal structure of phosphotriesterase (from Pseudomonas diminuta), which had the maximum sequence homology with VPg to identify the arrangement of conserved amino acids in the protein to study the functional diversity of VPg. This is the first report on the VPg of CdMV, which is classified as a new member of the Macluravirus genus of the Potyviridae family.