Organic Nitrogen Effects on Root Architecture in Rice Seedlings

The three land races viz. land races -1 (Lal Kada), land races -2 (Futiyu) and land races -3 (Kala Rata) were sown in organic media to investigate the uptake of nitrogen in the form of amino acid as substitute for inorganic nitrogenous fertilizers in their seedlings.The four concentrations (50%, 75%, 100% and 125%) of amino acid mixture (glycine, glutamic acid and aspartic acid) were applied to growing media and the roots architectural responses of 21 days of old seedlings were measured with the help of 2-D imaging software Ez-Rhizo after scanning of roots. Among four concentrations (50%, 75%, 100% and 125%) of amino acid mixture, the 100% amino acid mixture showed higher number of lateral roots, sum of lateral root length per seedling, lateral root angles, total root system size, mean lateral root length, lateral root density, nitrogen content in leaves and roots, root biomass and shoot biomass as compared to other percentage (50%, 75% and 125%) of amino acid mixtures. Moreover, land races -1 was found more responsive to amino acid mixture among the three land races

Molecular diversity analysis of rice (Oryza sativa L.) genotypes using RAPD and SSR marker

Random Amplified Polymorphic DNA (RAPD) and Simple Sequence Repeat (SSR) molecular markers were used for detecting the genetic variability of 20 rice genotypes using 79 SSRs and 30 RAPD primers. Among primers used, a set of 16 SSR and 14 RAPD markers showed polymorphism, and banding patterns were scored as 1 (present) or 0 (absent) in the datasheet which was further analyzed by using Jaccard’s similarity coefficient and SAHN clustering. The number of alleles, PIC value, and heterozygosity for individual 16 SSR and 14 RAPD markers were used to assess the degree of polymorphism among the rice genotypes. A total of 36 polymorphic loci were found in 16 polymorphic SSR markers and 77 polymorphic loci were observed in 14 polymorphic RAPD markers. The number of alleles produced per locus ranged from 2 (RM447, RM21, RM171, RM237, RM25, RM283, RM510, RM259, RM334, RM433, RM489, and RM212) to 3 (RM263, RM152, RM413, and RM3331) in 16 SSRs markers and 3 (OPR-05) to 9 (OPR-02 and OPC-06) in 14 RAPD. In SSRs, the PIC value diverse from 0.30 (RM447) to 0.58 (RM152) with an average of 0.38 per locus and an average value of heterozygosity (0.49). RAPD analysis showed an average PIC value of 0.78. Based on the information generated, the 20 rice genotypes were grouped into two main clusters in both the analysis of the marker. In SSR markers analysis, cluster I comprised 4 genotypes and cluster II comprised 16 genotypes and in RAPD cluster I was shown 2 genotypes and cluster II show 18 genotypes.</jats:p

Effects of Water Deficit Stress at the Tillering Stage of Direct Seeded Rice (Oryza sativa L.)

The ten rice varieties viz. NAUR-1, Purna, GNR-6, NVSR-2227, NVSR-3093, NVSR-2285, NVSR-2278, NVSR-2852, NVSR-2601, and NVSR-2927 were grown in kharif season for observing their efficiency in terms of yield under a deficit of water at tillering stage. The effects of short-term water stress on various morpho-physiological and biochemical traits viz. leaf area index, number of panicles, chlorophyll content, number of stomata, relative water content, abscisic acid, proline, glycine betaine, ascorbic acid, and harvest index content were studied and they were observed higher in Purna as compared to other nine varieties. However, Plant height and Ionic leakage were recorded lower in Purna as compared to other varieties. The abscisic acid as well as proline and glycine betaine content recorded maximum in Purna which might help in keeping hydration in cells during water deficit stress. Thus, with short-term water deficit stress at tillering stage, the variety Purna would be better in terms of breeding for tolerant variety as well as yield among ten rice varieties

Highly efficient metal-free ethylenediamine-functionalized fullerene (EDA@C₆₀) electrocatalytic system for enhanced hydrogen generation from hydrazine hydrate

Ethylenediamine functionalized C60 (EDA@C60) based electrocatalyst demonstrated for hydrazine oxidation and it shows more than double current density i.e. 20 mA cm−2 at an ultralow onset potential of 0.2 V vs. SCE with better stability over oxidized C60.</jats:p

Does plant root architecture respond to potassium nutrition under water stress? A case from rice seedling root responses

ABSTRACTThe root is the sensing organ for potassium (K) and water availability. We evaluated whether K availability influences root architecture and contributes to drought tolerance under moisture stress. Rice seedling growth was severely affected by low K availability under water stress, and the substantial reductions in root projected area, maximum width, and width to depth ratio were observed. High K availability helps maintain root top and bottom angles and reduces root steepness under mild water stress, but over K nutrition does not ensure higher seedling growth. Under severe water stress, the steepness was more regulated by water than K availability.</jats:p