Saturday, 26 February 2011

Improving zinc efficiency of cereals under zinc deficiency

Bhupinder Singh, Senthil Kumar A. Natesan, B. K. Singh and K. Usha
Current Science 88 (1): 36-44, 2005
Abstract
One of the widest ranging abiotic stresses in world agriculture arises from low zinc (Zn) availability in calcareous soils, particularly in cereals. Cereal species greatly differ in their zinc effici ency (ZE), defined in this article as the ability of a plant to grow and yield well under Zn deficiency. ZE has been attributed mainly to the efficiency of acquisition of Zn under conditions of low soil Zn availability rather than to its utilization or (re)-translocation within a plant. A higher Zn acquisition efficiency, further, may be due to either or all of the following: an efficient ionic Zn uptake system, better root architecture, i.e. long and fine roots with architecture favouring exploitation of Zn from larger soil volume, higher synthesis and release of Zn-mobilizing phytosiderophore by the roots and uptake of Zn-phytosiderophore complex. Seed Zn content has also been suggested to affect ZE. This article attempts to examine critically the scanty and scattered reports available on the status of Zn deficiency globally; morphological, biochemical and physiological basis of regulation of ZE in cereals and approaches to improve ZE in terms of grain productivity and grain Zn vis-à-vis its bioavailability under conditions of poor Zn availability. A causal relationship between important Zn-containing enzymes, viz. carbonic anhydrase (CA), Cu/Zn-superoxide dismutase (SOD) activities and ZE is reported in wheat and other cereal species. Enhanced production and release of Fe-mobilizing phyto-metallophores known as phytosiderophores (PS), is another mechanism relevant for cereal species in adaptation to zinc deficiency.

Variability and correlation studies in bush type French bean (Phaseolus vulgaris L) in relation to green pod yield

B. K. Singh, B. P. Singh and H. H. Ram
Progressive Horticulture 32 (2): 176-182, 2000
E-mail: bksinghkushinagar@yahoo.co.in
Abstract
Estimates of variability, heritability, genetic advance as percentage of mean and correlation were studied for 13 green pod yield and yield contributing traits in 43 indigenous and exotic strains of bush type French bean in randomized block design with three replications at Horticultural Research Centre, Patharchatta, Pantnagar, U.P. The range of various phenotypic and genotypic coefficient of variation, heritability in broad sense, expected genetic advance and genetic advance in percentage of mean were highest for green pod yield per plant. Green pod yield per plant was positively correlated with its maximum components except days to 50 % flowering, days to first green pod picking and number of nodes per plant, expressing higher phenotypic correlation than genotypic correlation as a result of environmental effects.

Riboluse-1,5-biphosphate carboxylase/oxygenase content and activity in wheat, rye and triticale

B. Singh and B. K. Singh
Biologia Plantarum 44 (3): 427-430, 2001
Abstract
Photosynthetic parameters were measured in triticale and its parents wheat and rye soluble protein content in leaves, riboluse-1,5-biphosphate carboxylase/oxygenase (Rubisco) content per fresh mass, total chlorophyll content, biomass yield, leaf area, leaf mass and specific leaf mass were higher but Rubisco content expressed as percentage of soluble protein, carboxylase activity, photosynthetic rate and stomatal conductance were significantly lower in rye than in wheat. Native-PAGE of Rubisco revealed that rye carboxylase was different from that of wheat. The difference was not related to either the small or large subunit of Rubisco but, may be, to the ionic and/or other properties of the Rubisco protein moiety. Triticale Rubisco was similar to wheat. For most of the studied physiological parameters, triticale showed much more similarity with wheat than with rye.
Keywords: Chlorophyll content, net photosynthetic rate, Secale cereale, stomatal conductance, Triticum aestivum, Triticale octoploide.