A Novel Genotype Independent Protocol for In Vitro Plant Regeneration from Mature Seed Derived Callus of Tall Fescue (\u3ci\u3eFestuca Arundinacea\u3c/i\u3e Schreb.)

Tall fescues (Festuca arundinacea Schreb.) are cool season forage and turf grasses of significant agricultural importance in different grassland countries. Genetic improvement of tall fescues by conventional selection procedures is slow, since these are predominantly, cross-pollinated, hexaploid and generally infertile (Jauhar, 1993). Genetic Engineering approaches for incorporation of agronomically useful traits may contribute to the development of improved tall fescue cultivars (Spangenberg et al., 1998). However for any genetic engineering studies, it is essential to develop a genotype-independent, reproducible and efficient in vitro plant regeneration protocol. In the present study, we analyzed the effects of different sterilization procedures for in vitro seed germination and studied the effects of different concentrations and combinations of 2,4-D and BAP on callus induction, growth and regeneration potential of two cultivars of tall fescue

Efficient \u3cem\u3eIn Vitro\u3c/em\u3e Regeneration System From Seed Derived Callus of Perennial Ryegrass (\u3cem\u3eLolium Perenne\u3c/em\u3e) And Annual Ryegrass (\u3cem\u3eLolium Multiflorum\u3c/em\u3e)

The commercially important ryegrasses in cool temperate climates throughout the world are annual ryegrass (Lolium multiflorum L.) and perennial ryegrass (Lolium perenne L). Improvements through conventional breeding have been slow as they are usually heterozygous and highly self-infertile. Hence, there is a need to use modern biotechnological tools to the development of improved rye grass cultivars for incorporating value added traits. Successful transformation of rye grasses has been done using suspension cells, which is time consuming and laborious (Spangenberg et al., 1995, 1998). We report here a rapid and highly efficient in vitro plant regeneration system from seed derived callus in annual and perennial rye grasses

Modular Self-Reconfigurable Robotic Systems: A Survey on Hardware Architectures

Modular self-reconfigurable robots present wide and unique solutions for growing demands in the domains of space exploration, automation, consumer products, and so forth. The higher utilization factor and self-healing capabilities are most demanded traits in robotics for real world applications and modular robotics offer better solutions in these perspectives in relation to traditional robotics. The researchers in robotics domain identified various applications and prototyped numerous robotic models while addressing constraints such as homogeneity, reconfigurability, form factor, and power consumption. The diversified nature of various modular robotic solutions proposed for real world applications and utilization of different sensor and actuator interfacing techniques along with physical model optimizations presents implicit challenges to researchers while identifying and visualizing the merits/demerits of various approaches to a solution. This paper attempts to simplify the comparison of various hardware prototypes by providing a brief study on hardware architectures of modular robots capable of self-healing and reconfiguration along with design techniques adopted in modeling robots, interfacing technologies, and so forth over the past 25 years

Physiological and genetic effects of gamma rays, ethylmethane sulphonate, hydrazine, cysteine and their combinations in Sorghum bicolor (L.) Moench

Vita.Seeds of two varieties of Sorghum bicolor (L.) Moench. Tx-414 and NM-31 were irradiated with 20, 35 and 50 kr of ⁶⁰Co gamma rays at Oak Ridge National Laboratory. Sees of TX-414 also were treated with several concentrations of hydrazine (HZ) and ethylmethane sulphonate (EMS), singly and in combinations, with and without cysteine, used as a pre- and post-treatment modifier. NM-31 was found to be more mutagen sensitive to gamma rays than TX-414, as evidenced by greater reductions in seed germination, primary root length, coleoptile length, seedling height and fertility in the M₁ generation and increases in the frequency of chlorophyll mutations in the M₂ generation. Hydrazine was found to be a highly efficient mutagen based on low seedling injury and seed sterility in the M₁ generation and high frequency of chlorophyll in the M₂ generation. The mean frequencies of viable mutations recovered from HZ, EMS and gamma ray treatments were 2.13%, 0.80% and 0.42% respectively. Combination treatments of gamma +HZ and EMS + HZ or HZ + EMS were found to be highly toxic though a less than additive effect was observed for the reduction in seed germination and seedling injury in the M₁ generation. Fertility reduction was more than additive in HZ+EMS and EMS+HZ treatments while it was less than additive in gamma + HZ treatments.

Physiological and genetic effects of gamma rays, ethylmethane sulphonate, hydrazine, cysteine and their combinations in Sorghum bicolor (L.) Moench

Vita.Seeds of two varieties of Sorghum bicolor (L.) Moench. Tx-414 and NM-31 were irradiated with 20, 35 and 50 kr of ⁶⁰Co gamma rays at Oak Ridge National Laboratory. Sees of TX-414 also were treated with several concentrations of hydrazine (HZ) and ethylmethane sulphonate (EMS), singly and in combinations, with and without cysteine, used as a pre- and post-treatment modifier. NM-31 was found to be more mutagen sensitive to gamma rays than TX-414, as evidenced by greater reductions in seed germination, primary root length, coleoptile length, seedling height and fertility in the M₁ generation and increases in the frequency of chlorophyll mutations in the M₂ generation. Hydrazine was found to be a highly efficient mutagen based on low seedling injury and seed sterility in the M₁ generation and high frequency of chlorophyll in the M₂ generation. The mean frequencies of viable mutations recovered from HZ, EMS and gamma ray treatments were 2.13%, 0.80% and 0.42% respectively. Combination treatments of gamma +HZ and EMS + HZ or HZ + EMS were found to be highly toxic though a less than additive effect was observed for the reduction in seed germination and seedling injury in the M₁ generation. Fertility reduction was more than additive in HZ+EMS and EMS+HZ treatments while it was less than additive in gamma + HZ treatments.

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Not AvailableNot AvailableICAR-IIHR, Bengalur

INDUS - a composition-based approach for rapid and accurate taxonomic classification of metagenomic sequences

Abstract Background Taxonomic classification of metagenomic sequences is the first step in metagenomic analysis. Existing taxonomic classification approaches are of two types, similarity-based and composition-based. Similarity-based approaches, though accurate and specific, are extremely slow. Since, metagenomic projects generate millions of sequences, adopting similarity-based approaches becomes virtually infeasible for research groups having modest computational resources. In this study, we present INDUS - a composition-based approach that incorporates the following novel features. First, INDUS discards the 'one genome-one composition' model adopted by existing compositional approaches. Second, INDUS uses 'compositional distance' information for identifying appropriate assignment levels. Third, INDUS incorporates steps that attempt to reduce biases due to database representation. Results INDUS is able to rapidly classify sequences in both simulated and real metagenomic sequence data sets with classification efficiency significantly higher than existing composition-based approaches. Although the classification efficiency of INDUS is observed to be comparable to those by similarity-based approaches, the binning time (as compared to alignment based approaches) is 23-33 times lower. Conclusion Given it's rapid execution time, and high levels of classification efficiency, INDUS is expected to be of immense interest to researchers working in metagenomics and microbial ecology. Availability A web-server for the INDUS algorithm is available at http://metagenomics.atc.tcs.com/INDUS/</p