Neerja Sharma

Effect of chlorocholine chloride sprays on the carbohydrate composition and activities of sucrose metabolising enzymes in potato (Solanum tuberosum L.)

Chlorocholine chloride (CCC) was sprayed on a potato crop 25 days after sowing (DAS) at 5 day intervals for a total of 7 sprays. Activity of sucrose synthase (SS) in the sucrose cleavage direction was many fold higher than that of acid invertase in all the tissues. The activity of alkaline invertase was negligible. A sharp decline in the starch content of stolons of the CCC-sprayed crop was observed between 60 DAS and 70 DAS. This could divert the carbon towards tubers and thus enhancing its availability for starch synthesis. The CCC-treated crop, in general, had higher SS (cleavage) activity in stem, stolons and tubers. A higher sucrose content in the stem of the CCC-treated crop could be due to the high sucrose phosphate synthase (SPS) activity observed in this plant part. In tubers of CCC-treated crops a higher SS (cleavage) activity along with a high sucrose content in tubers during the active tuber filling stage could lead to better availability of UDP-glucose for its conversion to glucose-1-phosphate, which could enter into the amyloplast leading to higher starch content. High SPS activity in tubers of CCC-treated plants ensures that reducing sugars formed are reconverted efficiently to sucrose. The efficiency of developing tubers from CCC-sprayed plants to convert 14C sucrose fed through stolons into starch was about 2.5 times more than in the control.

Effects of gibberellic acid and chlorocholine chloride on tuberisation and growth of potato (Solanum tuberosum L)

Treatment of potato plants with gibberellic acid (GA3) enhanced both shoot and stolon growth and dry weight but delayed tuber initiation and decreased tuber yield. Conversely, treatment with chlorocholine chloride (CCC) growth retardant reduced shoot and stolon growth and dry weight but promoted tuberisation. Chlorophyll a and b contents were both increased appreciably with CCC. In the tubers, CCC increased starch content by 11% compared to untreated control, whereas GA3 decreased starch content by about 13%. A very high reducing sugar content in the stem of GA3-treated crop indicated active hydrolysis of sucrose coming from the leaves, leading to its reduced supply to the tubers because of further possible sucrose hydrolysis while passing through the long stolons. However, in the CCC treated crop, the higher chlorophyll content of the leaves with reduced stolon length will promote efficient sucrose supply to the tubers.

Comparison of photoperiod-sensitive and photoperiod-insensitive basmati cultivars for grain yield, water productivity, and quality traits under varied transplanting dates in Northwest India

Abstract. In order to increase yield and water productivity, arrest the mining of groundwater, and achieve quality production in Northwest India, there is a need to optimise the transplanting time for newly evolved, high-yielding basmati cultivars. This study in the Indian Punjab was aimed at investigating the effect of date of transplanting (5, 15, and 25 July) on yield, quality traits, and water productivity of four basmati rice cultivars (Pusa Basmati 1121, Pusa Basmati1509, Punjab Basmati 3, and Basmati 386) varying in photoperiod sensitivity. Water productivity of Pusa Basmati1509 was higher than of photoperiod-sensitive cultivars (Punjab Basmati 386 and Punjab Basmati 3) for each transplanting date. Water productivity [irrigation, WPI; total (irrigation + rainfall), WPI+R; and real crop, WPET] of Punjab Basmati 3 for the 25 July transplanting was similar to Pusa Basmati 1509 for the 5 July transplanting. For the 25 July transplanting, WPI, WPI+R, and WPET of Pusa Basmati 1509 increased by 48.9%, 35.2%, and 22.5%, respectively, relative to Pusa Basmati 1121; by 34%, 31.4%, and 27.5% relative to Punjab Basmati 3; and by 81.1%, 70.4%, and 56% relative to Basmati 386. The study showed that delaying transplanting of photoperiod-sensitive and short-duration, photoperiod-insensitive basmati cultivars helped to improve water productivity and quality traits, particularly the head rice recovery (%), kernel length after cooking, and amylose content.

Red pericarp introgression lines derived from interspecific crosses of rice: physicochemical characteristics, antioxidative properties and phenolic content

BACKGROUND Antioxidative properties and physicochemical characteristics of introgression lines (ILs) and their recurrent parents were analyzed. In addition, catalase (CAT) and superoxide dismutase (SOD) activities and free radical-scavenging capacity were evaluated, since these are important antioxidative properties for developing nutraceutical and functional foods. RESULTS Comparative analysis of the brown and milled rice fractions of ILs with their respective recurrent parents revealed 2.26- and 1.22-fold increase in total phenolics, 1.95- and 2.09-fold increase in flavonoids, 8.38- and 6.80-fold increase in proanthocyanidins and 1.55- and 1.20-fold increase in tannins in brown and milled rice fractions respectively. Higher CAT (1.36- and 1.89-fold) and SOD (1.71- and 2.02-fold) activities and Trolox equivalent antioxidant capacity (TEAC, 7.13- and 1.98-fold) were observed in brown and milled rice fractions respectively of ILs compared with their respective recurrent parents. A high and positive correlation was obtained between TEAC and total phenols (0.73, P ≤ 0.01), flavonoids (0.66, P ≤ 0.05) and proanthocyanidins (0.69, P ≤ 0.05). The yield parameters and physicochemical characteristics of the grains, in general, were comparable in the ILs and their respective recurrent parents. CONCLUSION The ILs of rice reported in the present study exhibited significant positive differences in the content of phenolic constituents and antioxidant properties with good grain quality characteristics over their recurrent parents, indicating their potential as a natural source of phytochemicals for nutraceutical and functional food development.

Biochemical responses associated with bacterial blight of rice (Oryza sativa)

Biochemical response of susceptible cultivar TN 1 and resistant near isogenic lines IRBB 13 and IRBB 21 of rice to Xanthomonas oryzae pv. oryzae (Xoo) was studied at different stages of infection. The activities of the defence related enzymes peroxidase (PO), phenylalanine ammonia lyase (PAL) and tyrosine ammonia lyase (TAL) were found to be significantly higher in the resistant isogenic lines, IRBB 13 and IRBB 21 than in the susceptible cultivar TN 1. Total phenols, ortho-dihydroxyphenols and flavonols content also exhibited a similar trend as that of the enzymes. After bacterial infiltration a significant increase in the levels of total phenols, o-dihydroxyphenols, flavonols, PO, PAL and TAL was observed. However, this increase was comparatively rapid and higher in resistant near isogenic lines when compared with the susceptible line. Total sugars, reducing sugars and starch content were significantly higher in the leaves of the susceptible variety TN 1 than in the resistant near isogenic lines IRBB 13 and IRBB 21.

SMALL PUNCH TESTING: AN ALTERNATIVE TESTING TECHNIQUE TO EVALUATE TENSILE BEHAVIOR OF CORTICAL BONE

The tensile properties of cortical bone are usually determined with the help of uniaxial tensile test which requires enough amount of bone material. Further, it is very complicated to examine the heterogeneity and anisotropy associated with the deformational properties of cortical bone with the help of uniaxial tensile test. Through this study, small punch testing has been proposed as an alternate technique to evaluate the deformational behavior of cortical bone utilizing optimum amount of bone material. The comparison between elastic modulus values obtained from tensile test and stiffness values obtained through small punch testing was done for validation. The values of these properties were found to be having a significant positive correlation with each other. The effects of bone density and compositional parameters on these properties were also found to be having a similar trend. It is observed through this study that stiffness values from small punch technique are having a similarity with elastic modu...

Variation in the nutritional quality of rice straw and grain in response to different nitrogen levels

Abstract Nitrogen (N) applied through urea is essential for rice crops and usually it is the most yield-limiting nutrient in irrigated rice production around the world. A field experiment was conducted to evaluate the effect of nitrogen levels (0, 90,120, and 150 kg ha−1) on the nutritional quality of straw and grain of rice varieties, PR 111, PR 122, and Pusa 44. In rice straw, significant interaction between nitrogen levels and all proximate components was observed. Increase in nitrogen level increased the crude protein by 69.23% (dry matter basis) whereas the neutral detergent fiber, acid detergent fiber, and cellulose content decreased by 7.82%, 11.18%, and 14.16%, respectively. In rice grain, crude protein content, starch content, and gel consistency were positively related to increase in nitrogen levels. Therefore, increase in nitrogen fertilization led to improved nutritive quality of both straw and grain for use as feed resource and human consumption, respectively.

Heterotic response of genomic regions derived from Oryza rufipogon and O. nivara in improving grain morphology and quality of indica rice (Oryza sativa L.)

Limited backcrossing was followed to introgress useful variability, needed for improving grain morphology and milling traits, from wild Oryza species into two indica cultivars PR114 and Pusa44.These alien introgressions lines (ILs), having similar grain quality parameters to the recurrent parent, were used for developing rice hybrids to assess the effect of these introgressions in the heterozygous state and to assess their grain quality parameters, as most of the hybrids commercialized in the tropics have inferior grain quality. These ILs and their recurrent parents, possessing fertility restoration ability for wide abortive cytoplasm, were crossed with CMS line PMS 17A to generate introgressions line hybrids (ILHs). Hybrids developed from recurrent parents were used as a check to compare the performance of ILHs. Based on yield and phenotypic acceptability, six ILHs having enriched genome of O. rufipogon and O. nivara were selected and analyzed for grain quality traits. All six hybrids observed significant improvement in milled rice recovery (up to 10%), head rice recovery (up to 25%) over ILs and check hybrids. Introgressions were analyzed using polymorphic SSR markers. The majority of O. rufipogon and O.nivara alleles identified in the study seems to be effective across recipient genotypes and could be used effectively in quality breeding programs.

Induction of useful variability for pericarp colour and bacterial blight resistance in rice (Oryza sativa L.) cv. PAU 201 through EMS based mutagenesis

PAU 201, a high yielding variety of rice released by Punjab Agricultural University in 2007, was withdrawn from cultivation in the year 2010 mainly due to its red coloured pericarp. It also became susceptible to a new pathotype (PbXo-8) of bacterial blight (BB) pathogen. To improve these specific defects, PAU 201 was mutagenized with ethyl methane sulphonate in different concentrations of 0.6, 0.8 and 1.0% in water (v/v). A total of 841 M1 single panicles were harvested and advanced to M4 generation following selfing and selection for white pericarp colour in each generation. A set of promising 68 M4 progenies was also screened for BB resistance and one putative mutant possessing white pericarp colour as well as BB resistance (designated as RYT 3207) was identified. On further evaluation, RYT 3207 was found to be resistant to all the ten pathotypes of BB pathogen prevalent in the Punjab state and it yielded at par with the PAU 201 in multi-location trials during 2011 to 2013. Molecular marker analysis showed presence of xa13 locus in RYT 3207. The acquired resistance to all the ten pathotypes in RYT 3207, compared to nine pathotypes in PAU 201, could be due to modified function of xa13 gene. The new genotype RYT 3207 is a mutagenized version of the high yielding rice cultivar PAU 201 possessing white pericarp and enhanced resistance to bacterial blight.