Marker‐assisted introgression of bacterial blight and blast resistance into IR 58025B,an elite maintainer line of rice

IR 58025A is a very popular wild‐abortive cytoplasmic male sterile (WA‐CMS) line of rice and is extensively used for hybrid rice breeding. However, IR 58025A and many hybrids derived from it possess mild aroma (undesirable in some parts of India) and are highly susceptible to bacterial blight (BB) and blast diseases. To improve IR 58025A for BB and blast resistance, we have introgressed a major dominant gene conferring resistance against BB (i.e. Xa21) and blast (i.e. Pi54) into IR 58025B, the maintainer line of IR 58025A. An introgression line of Samba Mahsuri (i.e. SM2154) possessing Xa21 and Pi54 genes in homozygous condition and fine‐grain type was used as donor parent, and backcross breeding strategy was adopted for targeted introgression of the resistance genes. PCR‐based molecular markers tightly linked to Xa21 and Pi54 were used for selection of BB‐ and blast‐resistant lines, while closely linked markers were used for identification of backcross‐derived plants devoid of Rf4 and aroma. At BC₂F₅, four backcross‐derived lines possessing resistance against BB and blast, devoid of aroma, high yield, short plant stature, long‐slender grain type and with recurrent parent genome recovery ranging from 88.8% to 98.6% were selected and advanced for further evaluation. The improved versions of IR 58025B, viz. SB54‐11‐143‐9‐44‐5, SB54‐11‐143‐9‐44‐98, SB54‐11‐143‐9‐44‐111 and SB54‐11‐143‐9‐44‐171, behaved as perfect maintainers when test‐crossed with WA‐CMS lines. Agronomically superior lines of improved IR 58025B are being converted to CMS line through backcrossing for developing high‐yielding and biotic stress‐resistant rice hybrids.     

Sustainable Harvesting of Terminalia arjuna (Roxb.) Wight & Arnot (Arjuna) and Litsea glutinosa (Lour.) Robinson (Maida) Bark in Central India

Terminalia arjuna (“Arjuna”) in the family Combretaceae is a well-known medicinal tree whose bark is extensively used in Ayurvedic medicine, particularly as a cardiac tonic. Demand for Arjuna bark, both in India and abroad, has been growing rapidly for over a decade. Litsea glutinosa (“Maida”) in the family Lauraceae is a medium size tree. Its bark is used to treat joint pain, fracture, sprain, arthritis, back pain, and indigestion. Presently the bark of Arjuna and Maida is being extracted through unscientific and destructive harvesting practices. This is the first study on development of sustainable harvesting practices of Arjuna and Maida bark. The stages of bark recovery varied from tree to tree. Age of tree, harvesting method, and season of harvest influenced bark regeneration. This study recommends that for sustainable harvest, mature bark from only one fourth to one third of the total girth of the tree should be stripped by removing only outer and middle bark, leaving the inner bark for regeneration. However, strip harvesting was found to be the best method in younger trees having a girth at breast height (GBH) of less than 60 cm. Sustainable bark harvesting can be done after every 2 yr for Arjuna and 1 yr for Maida by removing opposite quarters of trunk bark.     

Application of Neutron Activation Analysis Technique for the Analysis of Soil Samples from Farmlands of Yebrage Hawariat,East Gojjam,Ethiopia

Farmers may not be conscious for their farmland＇s nutrients, soil organic matter, water and air because they simply concerned only for their labor availability and soil fertility losses. The composition and proportion of these components greatly influence soil physical properties, including texture, structure and porosity, the fraction of pore space in a soil. The soil of this farmland must be able to supply adequate amount of plant nutrients, in forms which can be absorbed by the crop, within its lifespan. Deficiencies or imbalances in the supply of any of essential elements can compromise growth, affecting root development, cell division, crop quality, crop yield and resistance to disease and drought. This study was conducted to fill this knowledge gap in order to develop economically vital and environmentally accepted nutrient management strategies for the use of soils in agricultural lands. The objective of this study is to assess the elemental contents and concentration of soil samples collected from farmlands of ＂Yebrage＂ using neutron activation analysis （NAA） techniques regardless of oxidation state, chemical form or physical locations. NAA is used to determine the elemental composition and concentrations present in a soil. The macro/micronutrient and organic matter deficiencies have been verified in agricultural soils through increased use of soil testing and plant analysis. The challenge for agriculture over the coming decades will meet the world＇s increasing demands for food in a sustainable way. Current issues and future challenges point out that as long as agriculture remains a soil based industry, major decreases in productivity likely to be attained ensuring that plants do not have adequate and balanced supply of nutrients.     

Microprojectile mediated plant transformation: A bibliographic search

This bibliographic search covers the literature till December, 1995 on microprojectile mediated plant transformation, plasmid construct used, and the type of expression obtained, since the inception of the concept by Sanford et al., in 1987. This revised version was published online in July 2006 with corrections to the Cover Date.     

Molecular cloning and characterization of lingual antimicrobial peptide cDNA of Bubalus bubalis

Antimicrobial peptides form a crucial component of innate immune system, making it a highly effective first line of defense in animals. In the study, lingual antimicrobial peptide cDNA of Bubalus bubalis has been characterized. The characterized cDNA has complete ORF of 195 bases. The signal sequence of buffalo LAP comprised of N-terminal 1-20 amino acids and mature peptide from 23-64 amino acids. The percentage of similarity of buffalo LAP and buffalo EBD at nucleotide and amino acid level was 96.4% and 92.3% respectively. The identity of buffalo LAP with cattle LAP and TAP at nucleotide level was 92.8% and 90.3%. Both at nucleotide and amino acid level buffalo LAP is closer to buffalo EBD followed by cattle LAP and TAP. Phylogenetic tree at nucleotide and amino acid level also showed close relationship of buffalo LAP with buffalo EBD, cattle LAP and TAP. The synthesized LAP fragment had antibacterial activity.