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Abstract : Cymbidiumaloifolium(L). Sw. is an exquisite epiphytic orchid of the Kolli Hills (Eastern Ghats) of Tamil Nadu in Southern India. It is fast disappearing from its natural habitats due to deforestation and low germination rate in natural habitat. In the present study, an attempt was made to germinate the seeds from un-dehisced capsule of Cymbidium aloifolium(L). Sw under in vitro condition. The seed germination and protocorm development were recorded in three different well known media namely Knudson C (KC), Half strength Murashige&Skoog (1/2 MS) and Vacin& Went (VW) media. The highest seed germination of 90% was observed KC basal media after 30^thdays whereas germination percentages were 40% and 30% on 1/2 MS and VW media respectively. The well-developed protocorm were transferred to KC media supplemented with 6-Benzyl Amino Purine (BAP) and Naphthalene acetic acid (NAA) where BAP (1.0 mg/l) and NAA (1.0 mg/l) together were found to be optimum for the highest shoot formation. About 90% of the shoots found to be well rooted after transfer to the KC medium differently supplemented with 1.5 mg/l Indole- 3-acetic acid (IAA) and 1.0 mg/l Indole-3-butyric acid (IBA). Though rooting also took place in the two basic media but the duration was longer when compared with the hormone-supplemented media. The rooted plantlets were hardened and kept under greenhouse conditions which can be relocated in natural habitats.

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Abstract : Purple passion fruit (PassifloraedulisSims) is one of the introduced tropical plants, an increasing interest has arisen due to its distinctive taste and attractive flavor. It is expected that passion fruit production and planted area will increase gradually in the years ahead because of high profitability and consumer’s demands of healthful ingredients. So we tried to investigate the effect of plant growth regulators and antioxidants on in vitroplant regeneration and callus induction from leaf explants of passion fruit for an establishment of optimal mass propagation system. Young leaf explants of purple passion fruit were cultured in Murashige and Skoog (MS) medium containing different growth regulators and antioxidant additives to induce the shoot organogenesis. After 8 weeks, the highest embryogenic callus formation rate was obtained in MS medium supplemented with 1 mg·L^-16-benzylaminopurine (BAP) and 2 mg·L^-12,4-dichloro- phenoxyacetic acid (2,4-D), furthermore, the shoot development via organogenesis was also observed. Silver nitrate (AgNO₃), which was added into the medium to minimize the adverse effects of leached phenolics, was effective for reduction of medium browning and sudden explant death. In the medium supplemented with 1 mg·L^-1BAP and 1 mg·L^-1gibberellic acid (GA₃), shoots were most vigorously regenerated and elongated. Most shoots rooted successfully in half strength medium with 1 mg·L^-1indol-3 acetic acid (IAA), and more than 90% of plantlets survived after 4-month acclimatization period.

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Abstract : To investigate optimal conditions for plant regeneration in Platycodon grandiflorum (Jacq. A. DC.). Both leaf and hypocotyl explants were cultured on Murashige& Skoog’s (MS) medium supplemented with combinations of 0.1, 0.5, 1.0, or 2.0 mg/L cytokinins (BA and kinetin) and 1.0 mg/L 2,4-D for 6 weeks, respectively. According to the type of explant, the total shoot organogenesis (56.38%) in leaf explants was higher than in hypocotyls (28.20%). In comparison with kinetin and BA for the plant regeneration, the frequency (70.38%) of leaf explants was higher in combination with kinetin and 2,4-D than of BA with 2,4-D (42.38%), whereas the frequency (35.56%) of hypocotyls explants was higher in BA combination than kinetin combination (20.83%). Thehighest frequency (94.20%) was observed from the cultures of leaf explants on the MS medium supplemented with 1.0 mg/L kinetin and 1.0 mg/L 2,4-D. Upon transfer onto ½ MS basal medium containing 3% sucrose, shoots developed into plantlets with roots, and were well grown in soil in the greenhouse. These results lead us to speculate that the optimization of culture conditions was responsible for the mass propagation from in vitro cultures of Platycodon grandiflorum (Jacq. A. DC.).

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Abstract : A micropropagation method via callus for Ranunculus kazusensis Makino, an endangered species, was established. When stem segments were cultured on MS media supplemented with 1.0 mg/L IAA, NAA, IBA and 2,4-D, the highest frequency of callus induction was achieved on MS medium supplemented with 1.0 mg/L NAA. Multiple shoot per explant was obtained, the MS medium containing 1.0 mg/L BA and 0.5 mg/L NAA. Additionally, effect of activated charcoal (AC) and sucrose on shoot growth in in vitro culture were examined. The most suitable conditions for shoot growth after 4 weeks of culture were the MS medium with AC and sucrose. This in vitro propagation protocol will be valuable for conservation and mass propagation of this endangered plant.

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Abstract : Development of modern agricultural machinery and accompanying agricultural development cause soil compaction and reduce growth by stressing roots. Kalanchoe pinnata was used to investigate the impact of stress on rooting and changes in plant growth and reproduction. K. pinnata forms somatic embryos capable of asexual reproduction at the edge of leaves. Impact of root pressurization of K. pinnata on somatic embryogenesis and organ differentiation according to external stress factors was investigated by using a high concentration of agar and this phenomenon was studied histologically. Agar concentration in culture media ranged from 0.5%-1.5% to induce a compression effect on roots. The stem and leaf of K. pinnata were subjected to a microtechnique process to study changes in tissue. In vivo, K. pinnata produced 2nd and 3rd plantlets at edges of leaves from lack of water and excessive lighting conditions. In in vitro culture studies, the lower the concentration of agar, the higher the population and the higher the biomass, but plantlet did not occur in leaf bends. Conversely, as concentration of agar increased, increase in the number of individuals was low. Plantlet development occurred only in agar 1.5% medium. The difference in agar concentration was a stressor in the root of K. pinnata, and thus the pattern of asexual reproduction changed from the division method in root to a plantlet generation in leaf. This suggests root pressurization may act as stress and change in the plant reproduction pattern.

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Abstract : The need to preserve and use plant genetic resources is widely recognized, and the prospect of dwindling plant genetic diversity, coupled with increased demands on these resources, has made them a topic of global discussion. In the present study, the genetic diversity and population structure of 73 ginseng accessions collected from six regions in China were analyzed using eight simple sequence repeat (SSR) markers. Major allele frequencies ranged between 0.38 ~ 0.78, with a mean allele frequency value of 0.571. The number of alleles discovered ranged from 3 to 10 per accession, with a mean number of 7; 56 alleles were discovered in total. Gene diversity (GD) and polymorphic information content (PIC) values were similar to each other, and they ranged from 0.36 ~ 0.77 (mean 0.588) and 0.33 ~ 0.74 (mean 0.548), respectively. Accessions were divided into three clusters based on their phylogenetic relationships and genetic similarities, and although the populations were similar, they were not classified according to the region. Regional genetic diversity was also similar, with slight differences observed based on the number of accessions per region. It is expected that the findings of the present study can provide basic data for future studies on ginseng genetic diversity and for breeding ginseng cultivars.

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Abstract : In this study, random amplified polymorphic DNA (RAPD) and sequence-related amplified polymorphism (SRAP) analyses were used for evaluation of genetic diversity of 61 kiwifruit (Actinidia spp.) germplasms including domestic and overseas collection cultivars. Forty RAPD primers were detected in a total of 230 polymorphic bands with an average of 5.75. Thirty-two SRAP primer combinations were detected in a total of 204 polymorphic bands with an average 6.38. By unweighted pair-group method arithmetic average cluster analysis using 434 polymorphic bands, kiwifruit germplasms were classified in three groups with similarity value of 0.680. Cluster I consisted of 46 kiwifruit germplasms belonging to A. deliciosa, A. chinensis, A. deliciosa × A. arguta, A. chinensis × A. arguta, and A. chinensis × A. deliciosa. Cluster II consisted of seven germplasms belonging to A. arguta and ‘Skinny Green’, a cultivar derived from a cross between A. arguta and A. deliciosa. Cluster III consisted of seven germplasms belonging to A. rufa, A. hemsleyana, A. macrosperma, A. polygama, and A. eriantha. Genetic similarity values among tested kiwifruit germplasms ranged from 0.479-0.991, and average similarity value was 0.717. Similarity value was highest (0.991) between NHK0038 (A. deliciosa) and NHK0040 (A. deliciosa), and lowest (0.479) between ‘Hayward’ (A. deliciosa) and K5-1-22 (A. arguta).

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Abstract : Rice (Oryza sativa) cultivars show an impairment of growth and development in response to abiotic stresses such as drought, salinity, heat and cold at the early seedling stage. The tolerance to heat stress in plants has been genetically modulated by the overexpression of heat shock transcription factor genes or proteins. In addition to a high temperature-tolerance that has also been altered by elevating levels of osmolytes, increasing levels of cell detoxification enzymes and through altering membrane fluidity. To examine the heat tolerance in transgenic rice plants, three OsOPT10 overexpressing lines were characterized through a physiological analysis, which examined factors such as the electrolyte leakage (EL), soluble sugar and proline contents. We further functionally characterized the OsOPT10 gene and found that heat induced the expression of OsOPT10 and P5CS gene related proline biosynthesis. It has been suggested that the expression of OsOPT10 led to elevated heat tolerance in transgenic lines.

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Abstract : Water temperature is one of the major factors that impacts the growth and life cycle of Pyropiatenera, one of the most valuable and cultivated marine red algae belonging to Bangiales (Rhodophytes). We analyzed transcriptome from gametophyte of P. teneraunder normal and high temperature conditions, and identified four small heat shock proteins (sHSPs). They have no significant amino acid sequence homology with known proteins in public databases except PhsHSP22 from Pyropiahaitanensis. PtsHSP19.3gene responded to high temperature but slightly or not to desiccation, freezing or high salt condition. When the PtsHSP19.3gene was overexpressed in Chlamydomonasreinhardtii, transformed Chlamydomonaslines revealed much higher growth rate than that of control cells under heat stress condition. Transformed cells also grew well in those of the control cell onto the medium containing high salt or H₂O₂. When the PtsHSP19.3was fused to GFP and introduced into tobacco protoplast, fluorescence was detected at several spots. Results indicate that PtsHSP19.3 may form super-molecular assembles and be involved in tolerance to heat stress.

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Abstract : GROWTH-REGULATING FACTOR(GRF) genes encodeplant-specific transcription factors containing two conserved QLQ and WRC domains and play criticalroles inregulating the growth and development of lateral organs, such as cotyledons, leaves, and flowers. Toexplore the agricultural potential of Brassica rapa GRF genes(BrGRFs), the researchersisolatedseven BrGRFs(BrGRF3-1, 3-2, 5, 7, 8-1, 8-2, and 9)and constructed BrGRF-overexpressing Arabidopsis thaliana plants (BrGRF-OX). BrGRF-OXplants developed larger cotyledons, leaves, andflowers as well as longer rootsthan the wild type. The increase in size of these organs were due to increases in cell number, but not due to cell size. BrGRF-OXplants alsohad larger siliquesand seeds. Furthermore, BrGRF-OXseeds produced more oil than the wild type. RT-PCR analysis revealed that BrGRF sregulatedexpression of a wide range ofgenes thatare involved in gibberellin-, auxin-, cell division-related growth processes. Taken together, thedata indicates that BrGRF sact aspositive regulators of plant growth, thus raising the possibility thatthey may serve as a useful genetic source for crop improvement with respect toorgan size and seed oil production.