Evaluation of Genetic Diversity in Chlorophytum borivilianum (Santp. and Fernan.) Using Molecular Markers: An Endangered Medicinal Plant

Chlorophytum borivilianum is a traditional medicinal plant distributed throughout the tropics and subtropics. In the present investigation, RAPD and ISSR analyses were used to assess the genetic diversity among 21 accessions collected from different geographical regions of India using 20 RAPD primers and 6 ISSR primers. RAPD and ISSR primers revealed 92.26% and 82.76% polymorphism, respectively. Similarity in coefficient values ranged from 0.321 to 0.707 for RAPD and 0.363 to 0.846 for ISSR markers. The dendrogram developed by RAPD and ISSR marker‐based analysis grouped the 21 accessions into different clusters. Mantel test employed for detection of goodness of fit established the cophenetic correlation value for both the primer systems and it was observed to be significant. Clustering of accessions within groups was also similar based on RAPD‐ and ISSR‐derived dendrograms. In our study, both marker systems were similar except for the percentage polymorphism which was found to be greater using RAPD, thus indicating the greater effectiveness of RAPD primers for estimating genetic variation of C. borivilianum

Hybrid Rice Research: Current Status and Prospects

Heterosis is a solitary means of exploiting hybrid vigor in crop plants. Given its yield advantage and economic importance, several hybrids in rice have been commercialized in more than 40 countries, which has created a huge seed industry worldwide. India has made commendable progress and commercialized 117 three-line indica hybrids for different ecology and duration (115–150 days), which accounted for 6.8% of total rice area in the country. Besides, several indigenous CMS lines developed in diversified genetic and cytoplasmic backgrounds are being utilized in hybrid rice breeding. NRRI, which has been pioneering to start with the technology, has developed three popular rice hybrids, viz., Ajay, Rajalaxmi, and CR Dhan 701 for irrigated-shallow lowland ecosystem. Biotechnological intervention has supplemented immensely in excavating desirable genomic regions and their deployment for further genetic enhancement and sustainability in rice hybrids. Besides, hybrid seed production creates additional job opportunity (100–105 more-man days) and comparatively more net income (70% more than production cost) than HYVs. Hence, this technology has great scope for further enhancement in per se rice productivity and livelihood of the nation

Identification and characterization of polymorphic genic SSR markers between cultivated (Oryza sativa) and Indian wild rice (Oryza nivara)

299-310In the present study, we developed a set of 100 BC2F4 mapping lines derived from the cross between the Oryza nivara (AC100476) and high yielding indica rice, Lalat. Out of 410 RM markers used for polymorphism survey between the parental lines, we identified around 113 (28.9%) polymorphic rice microsatellite (RM) markers between the parental lines that were uniformly distributed among the 12 chromosomes except for few gaps on chromosome 1, 7 and 10. On the basis of motif length, the trinucleotide repeats-motif, (TTA)n was the longest with a maximum motif length of 177 nucleotides. Among the repeat motifs, di-nucleotide repeat-motifs was the most abundant (68.14%) with the motifs (AC/GT)n were the most abundant accounting 56.32% of the total dinucleotide repeat-motifs. Out of the 113 polymorphic RM markers, 56 (49.55%) were found to be genic markers and broadly distributed into three groups such as molecular, biological and cellular categories with 38%, 32% and 30% frequencies, respectively. The present finding would be useful for the identification and mapping of drought related traits and development of drought tolerant rice cultivars in rice breeding program

Factors influencing rapid clonal propagation of Chlorophytum arundinaceum (Liliales: Liliaceae), an endangered medicinal plant

Chlorophytum arundinaceum is an important medicinal plant and its tuberous roots are used for various health ailment treatments. It has become an endangered species in the Eastern Ghats, and a rare medicinal herb in India, due to its excessive collection from its natural habitat and its destructive harvesting techniques, coupled with poor seed germination and low vegetative multiplication ratio. In order to contribute to its production systems, an efficient protocol was developed for in vitro clonal propagation through shoot bud culture. For this, multiple shoots were induced from shoot bud explants on Murashige and Skoog's medium supplemented with 2.5-3.0mg/L BAP, 0.01-0.1mg/L NAA and 3% (w/v) sucrose. Inclusion of Adenine Sulphate (25mg/L) in the culture medium improved the frequency of multiple shoot production and recovered the chlorotic symptoms of the leaves. Media having pH 5.9 and 4% sucrose showed significant improvement on shoot bud multiplication and growth. In vitro flowering was observed when the subcultures were carried out for over four months in the same multiplication media. Rooting was readily achieved upon transferring the shoots on to half- strength MS medium supplemented with 0.1mg/L IBA and 2% (w/v) sucrose. Micropropagated plantlets were hardened in the green house, successfully established, and flowered in the field. This method could effectively be applied for the conservation and clonal propagation to meet the demand of planting materials. Rev. Biol. Trop. 59 (1): 435-445. Epub 2011 March 01

Differential nickel tolerance of mung bean (Vigna radiata L.) genotypes in nutrient culture

Eight cultivars of mung bean (Vigna radiata L.) were tested for their tolerance to different levels of nickel (Ni) (0, 6, 12, 18 and 24 μM) in nutrient solution at pH 6.8. Seeds were germinated and grown in the presence of nickel under controlled environmental conditions. Standard growth parameters such as root length, shoot length, root/shoot dry biomass production and root/shoot tolerance index were used as markers of nickel toxicity. Measurements as early as 24 h after the beginning of treatment did not yield consistent results. However, root measurements 3, 6 and 9 days after the beginning of treatments yielded significant differences among cultivars which were similar to field performance in nickel-rich soils. The cultivars Dhauli and PDM-116 showed root growth while LGG-407, K-851, TARM-22 and TARM-1, TARM-21, TARM-26 exhibited a reverse trend in root growth in the presence of nickel (12 μM). The root tolerance index (RTI) and the shoot tolerance index (STI) with respect to Dhauli and PDM-116 were high indicating their tolerance to nickel; TARM-21 and TARM-26, however, showed a low RTI and STI. Based on the growth parameters eight cultivars of mung bean were ranked with respect to their tolerance to nickel: Dhauli > PDM-116 > LGG-407 > K-851 > TARM-22 > TARM-1 > TARM-21> TARM-26. Nickel induced greater G6PDH and GDH activity in Dhauli and PDM-116 as compared to LGG-407, K-851, TARM-22, TARM-1, TARM-21 and TARM-26. This method can be employed for quick screening of mung bean for nickel tolerance. (© Inra/Elsevier, Paris.)Tolérance au nickel de divers génotypes de haricot mungo (Vigna radiata L.) cultivés sur solution nutritive. On a testé la tolérance de huit cultivars de haricot mungo à divers niveaux de nickel (Ni) (0, 6, 12, 18 et 24 μM) présents dans une solution nutritive à pH 6,8. Les graines ont germé et se sont développées en présence de nickel en conditions de milieu contrôlées. Les paramètres standard de la croissance, tels que la longueur des racines, la longueur des pousses, la production de biomasse des racines et celle des pousses, l'indice de tolérance des racines et celui des pousses, ont été utilisés comme marqueurs de la toxicité du Ni. Les mesures faites 24 h après le début du traitement n'ont pas donné de résultats cohérents. La mesure des racines 3, 6 et 9 j après le début du traitement a donné des différences significatives entre cultivars qui avaient les mêmes performances au champ dans des sols riches en Ni. Les cultivars Dhauli et PDM-116 ont présenté une croissance racinaire en présence de Ni, tandis que la tendance était inverse pour LGG-407, K-851, TARM-22 et TARM-1, TARM-21 et TARM-26. L'indice de tolérance des racines (RTI) et celui des pousses (STI) indiquaient nettement une tolérance au Ni pour Dhauli et PDM-116 ; TARM-21 et TARM-26, en revanche, avaient un RTI et un STI faibles. La tolérance au Ni des huit cultivars, basée sur les paramètres de la croissance a donné le classement suivant : Dhauli > DDM-116 > LGG-407 > K-851 > TARM-22 > TARM-1 > TARM-21 > TARM-26. Le nickel a provoqué une plus grande activité enzymatique de la glucose-6-phosphate déshydrogénase et de la glutamate déshydrogénase chez Dhauli et PDM-116 comparé aux autres cultivars. Cette méthode peut être utilisée pour un criblage rapide du haricot mungo à la tolérance au nickel.(© Inra/Elsevier, Paris.

Regeneración de plantas a partir de cultivos de callos de Vitex trifolia (Lamiales: Lamiaceae): una planta medicinal potencial

Vitex trifolia is a shrub species with popular use as a medicinal plant, for which leaves, roots and flowers have been reported to heal different distresses. The increasing exploitation of these plants has endangered its conservation, and has importantly justified the use of biotechnological tools for their propagation. Our aim was to present an efficient protocol for plant regeneration through organogenesis; and simultaneously, to analyze the genetic homogeneity of the established clonal lines by Randomly Amplified Polymorphic DNA (RAPD) and Inter Simple Sequence Repeat (ISSR) markers. Plantlet regeneration was achieved in callus cultures derived from stem, leaf and petiole explants of V. trifolia on a differently supplemented Murashige & Skoog medium, and incubated at 25±2ºC under a light intensity of 61μmol/m2s from cool white fluorescent lamps and a 16h photoperiod. The rate of shoot bud regeneration was positively correlated with the concentration of hormones in the nutrient media. Shoot buds regenerated more rapidly from stem and petiole explants as compared to leaf explants on medium containing 11.10μM BAP in combination with 0.54μMNAA. Addition of 135.74-271.50μM adenine sulphate (Ads) and 0.72-1.44μM gibberellic acid (GA3) to the culture medium increased the growth of shoot buds. The highest rate of shoot bud regeneration responses was obtained in stem explants using 11.10μM BAP in combination with 0.54μM NAA, 271.50μM Ads and 1.44μM GA3. In vitro rooting of the differentiated shoots was achieved in media containing 1.23μM indole butyric acid (IBA) with 2% (w/v) sucrose. Regenerated plantlets were successfully established in soil with 86% survival under field condition. Randomly Amplified Polymorphic DNA and Inter Simple Sequence Repeat markers analyses have confirmed the genetic uniformity of the regenerated plantlets derived from the second up to fifth subcultures. This protocol may help in mass propagation and conservation of this important medicinal plant of great therapeutic potential.Vitex trifolia es una especie arbustiva de uso popular como planta medicinal, sus hojas, raíces y flores se han reportado para la cura de diferentes aflicciones. El aumento de la explotación de estas plantas ha puesto en peligro su conservación y ha justificado el uso de herramientas biotecnológicas para su propagación. El objetivo de esta investigación fue presentar un protocolo eficiente para la regeneración de estas plantas a través de la organogénesis, y analizar la homogeneidad genética de las líneas clonales establecidas por ADN polimórfico amplificado aleatoriamente (RAPD) mediante la repetición de marcadores de inter secuencia simple (ISSR). La regeneración de plántulas se logró en cultivos de callos derivados de explantes de tallo, hoja y pecíolo de V. trifolia en un medio diferenciado Murashige & Skoog, que se incubaron a 25±2ºC bajo una intensidad de luz de 61μmol/m2s con lámparas fluorescentes blancas y un fotoperíodo de 16h. La tasa de regeneración de brotes se correlacionó positivamente con la concentración de las hormonas en el medio nutritivo. Los brotes se regeneraron más rápidamente a partir de explantes de tallo y pecíolos en comparación con explantes de hoja. La mayor tasa de regeneración de brotes se obtuvo en los explantes de tallo utilizando 11.10μM BAP en combinación con 0.54μM NAA, 271.50μM Ads y 1.44μM GA3. Este protocolo puede ayudar a la propagación masiva y conservación de esta importante planta medicinal de gran potencial terapéutico

Plant regeneration from callus cultures of Vitex trifolia (Lamiales: Lamiaceae): a potential medicinal plant

Vitex trifolia is a shrub species with popular use as a medicinal plant, for which leaves, roots and flowers have been reported to heal different distresses. The increasing exploitation of these plants has endangered its conservation, and has importantly justified the use of biotechnological tools for their propagation. Our aim was to present an efficient protocol for plant regeneration through organogenesis; and simultaneously, to analyze the genetic homogeneity of the established clonal lines by Randomly Amplified Polymorphic DNA (RAPD) and Inter Simple Sequence Repeat (ISSR) markers. Plantlet regeneration was achieved in callus cultures derived from stem, leaf and petiole explants of V. trifolia on a differently supple mented Murashige & Skoog medium, and incubated at 25±2ºC under a light intensity of 61µmol/m2s from cool white fluorescent lamps and a 16h photoperiod. The rate of shoot bud regeneration was positively correlated with the concentration of hormones in the nutrient media. Shoot buds regenerated more rapidly from stem and petiole explants as compared to leaf explants on medium containing 11.10µM BAP in combination with 0.54µMNAA. Addition of 135.74-271.50µM adenine sulphate (Ads) and 0.72-1.44µM gibberellic acid (GA3) to the culture medium increased the growth of shoot buds. The highest rate of shoot bud regeneration responses was obtained in stem explants using 11.10µM BAP in combination with 0.54µM NAA, 271.50µM Ads and 1.44µM GA3. In vitro rooting of the differentiated shoots was achieved in media containing 1.23µM indole butyric acid (IBA) with 2% (w/v) sucrose. Regenerated plantlets were successfully established in soil with 86% survival under field condition. Randomly Amplified Polymorphic DNA and Inter Simple Sequence Repeat markers analyses have confirmed the genetic uniformity of the regenerated plantlets derived from the second up to fifth subcultures. This protocol may help in mass propagation and conservation of this important medicinal plant of great therapeutic potential