Emergence of multiple seedlings from seed of Garcinia mangostana L. (Clusiaceae).

Polyembryony is the formation of multiple embryos in a single seed. It was reported to occur in Garcinia mangostana through sporophytic adventitious embryony. This paper reports new insight of multiple shoot formation on seed of G. mangostana and a different finding compare to previous studies. A germination study was carried out during the July to August mangosteen fruiting season at University Agriculture Park, Universiti Putra Malaysia. Ten trees were randomly selected and 20 fruits samples were collected. From each fruit, only the biggest seed was used. Seed was disinfected using benomyl and sown on sterilized sand. Flower buds and flowers were also collected. Histological studies were carried out following the TBA series and dyed with Fast Green and Safranin O. For scanning electron microscopy (SEM) observations, samples were fixed in 70% formalin acetic acid and dehydrated using critical point dryer. Samples were mounted on aluminum stubs and finally coated twice with gold for two minutes. The percentage of seed germination was 47% and from that 11% of seeds were with multiple shoots. The morphology of the mangosteen seed was made of hypocotyl with two long strips of vascular bundle. From the histology and SEM, it was shown that shoot and root arises from the end of the vascular bundle. It was also observed that in some instance there were two ovules per locule that further developed into hypocotyls. The hypocotyls carrying their own vascular bundles will unite and enclosed by a single testa and form the “seed”. From each hypocotyl single shoot will emerged. When there are two to three hypocotyls united, two to three shoot will emerged thus displaying multiple shoots per seed. This study concluded that the term polyembryony is not suitable because there was only a single embryo per hypocotyl

Floral biology, flowering behaviour and fruit set development of Jatropha curcas L. in Malaysia

This paper describes the flowering behaviour of Jatropha curcas cultivated under Malaysian tropical climate. Investigation was carried out by observing the floral morphology, flowering sequence of pistillates, floral anthesis time, flower daily anthesis, flowering and fruiting plant behaviour, flower sex and fruit set ratio. Floral reproductive organs were examined using Scanning Electron Microscope (SEM). Jatropha is monoecious and it produces individual flowers in a dichasial cyme. Each Jatropha inflorescence has at least six compound cymes. The male flower anthesis started the earliest at 12.00 am and once again at 6.10 am to 6.46 am. The female flower anthesis commenced at 6.35 am to 8.25 am. The male flowers opened for a period of 8 to 11 days, while the female flowers opened for only 3 to 4 days. The reading of the male to the female flower ratio was taken twice, 22:1 in December 2008 and 27:1 in April 2009. The flower to fruit ratios were 6:5 (January 2009) and 2:1 (May 2009). Numerically, 0-10 female flowers and 25-215 male flowers are produced in the same inflorescence. In this study, the terminal stem of Jatropha bore fruits profusely in January, May and August 2009. Meanwhile, the development of the floral meristem consists of three stages which include a vegetative stage, a transition from vegetative to floral stage and development of flower parts. The meristem was in the transition stage at day 6. Although all sepals and a petal were developed at day 18, the presence of reproductive organs developing at this particular stage was not detected. Flower and fruit development took approximately 3 months to complete the full cycle, i.e. from the initiated floral bud stage until fruit maturity

A new Vanilla species from Peninsular Malaysia

A new species, Vanilla sanguineovenosa R. Go & A. Raffi, from Peninsular Malaysia is described, illustrated, and other aspects of interest discussed. It is so far known from a small population in lower montane forests at Tapah, Perak. A field key to the Peninsular Malaysian taxa, including V. sumatrana is also provided

Molecular evidence in identifying parents of Garcinia mangostana L.

The obligate apomicts Garcinia mangostana L. (Clusiaceae) was described from Malaysia and hypothesized to have originated from the natural hybridization between G. malaccensis and G. hombroniana. One of the parents, i.e. G. malaccensis, was believed to be endemic in the state of Melaka. However, this was determined only through a comparison of their chromosome number and morphological characteristics. There is still the possibility of other species within the same section of G. mangotana as the possible parents. Thus, investigations were carried out using molecular markers from three different regions of the internal spacer, chloroplast and micorsatellite. The objective of this study was to identify the possible parents of G. mangostana by comparing its relationship to other species within the same section, based on the genetic analysis of the internal spacer, chloroplast and microsatellite regions. Meanwhile, comparisons of allele sizes between G. mangostana with G. malaccensis, G. opaca and G. hombroniana using six polymorphic primers which had previously been developed were also performed. For phylogenetic analysis ITS, trnL and accD-psaL primers were used to determine the relationships between the four Garcinia species in the Garcinia section with two other sections and the genus Clusia as an outgroup. From the genetic analysis, it was found that G. hombroniana shares no common allele with the other species, while G. opaca has similar allele sizes with G. mangostana and G. malaccensis. The phylogenetic tree also showed that the closest relative to G. mangostana is G. opaca and G. malaccensis. This proves that G. opaca is more likely to be the other parent of G. mangostana rather than G. hombroniana

An efficient in vitro plantlet regeneration from shoot tip cultures of Curculigo latifolia, a medicinal plant

A procedure was developed for in vitro propagation of Curculigo latifolia through shoot tip culture. Direct regeneration and indirect scalp induction of Curculigo latifolia were obtained from shoot tip grown on MS medium supplemented with different concentrations and combinations of thidiazuron and indole-3-butyric acid. Maximum response for direct regeneration in terms of percentage of explants producing shoot, shoot number, and shoot length was obtained on MS medium supplemented with combination of thidiazuron (0.5 mg L−1) and indole-3-butyric acid (0.25 mg L−1) after both 10 and 14 weeks of cultures. Indole-3-butyric acid in combination with thidiazuron exhibited a synergistic effect on shoot regeneration. The shoot tips were able to induce maximum scalp from basal end of explants on the medium with 2 mg L−1 thidiazuron. Cultures showed that shoot number, shoot length, and scalp size increased significantly after 14 weeks of culture. Transferring of the shoots onto the MS medium devoid of growth regulators resulted in the highest percentage of root induction and longer roots, while medium supplemented with 0.25 mg L−1 IBA produced more numbers of roots

Seed quality of soybean in relation to Phomopsis seed decay in Malaysia.

Phomopsis Seed Decay (PSD) is detrimental for seed quality in soybean. In this study, three varieties of soybean were evaluated to determine their sensitivity to PSD and its influence on seed quality. These varieties were planted in a factorial experiment with three replication in two plant densities and two seasons in University Putra Malaysia. The incidence of Phomopsis was determined using culture plate method. Seed quality was tested using standard germination test, tetrazolium test and electrical conductivity. Most colonies were morphologically similar with Phomopsis longicolla. Infection to Phomopsis and seed viability was significantly different between soybean varieties and plant densities in two seasons. The AGS 190 with 46% showed the most percentage of Phomopsis in higher plant density in the second season. Pershing had 10% infection in lower plant density in the first season and showed more tolerance to Phomopsis in this study. Higher plant density caused higher infection to PSD, lower percentage of seed viability and more electrical conductivity. Standard germination and tetrazolium test were 76 and 72% in higher plant density respectively. Electrical conductivity was 83 μS cm-1 g-1 in higher plant density whereas it was 68 μS cm-1 g-1 in lower plant density. Phomopsis incidence showed negative correlation with seed viability and it was positively correlated with electrical conductivity. Based on these relationships, Pershing with its low Phomopsis infection showed the highest seed viability. The values for viability were 84 and 82%. This study indicates that the incidence of Phomopsis seed decay is usually dependent on field environments and planting densities. The severity of infection is also dependent on the variety

Seed traits and germination behaviour of kemunting (Rhodomyrtus tomentosa) populations as affected by different temperatures

To examine the variation in seed morphometric traits as well as germination performance at a range of temperatures (10-40°C), Rhodomyrtus tomentosa seeds were collected from four locations across Peninsular Malaysia (designated (C-02), (K-03), (M-01) and (T-01)). Seed source had a significant effect on seed morphometric traits with seeds from K-03 recording the highest values and seeds from C-02 the lowest values for seed length, seed width, seed thickness and 1000 seed weight. These differences in seed traits, which were attributed to maternal or environmental effects, influenced the rate of water uptake leading to variation in germination behaviour such as germination percentage (GP), days to first germination (GD) and time to 50% germination (T50) of the seeds from the four locations. Temperature significantly affected GP, GD and T50 but the effect of location was only significant for GD and T50. There were significant interaction effects of location × temperature for all the parameters tested. Generally, R. tomentosa seeds showed a slow increase in water uptake due to the presence of the operculum and the mesotesta which consists of sclerified cells, and had erratic germination behaviour

Optimum shade enhances growth and 5,7-dimethoxyflavone accumulation in Kaempferia parviflora Wall. ex Baker cultivars

Light is one of the main limiting factors for phenolic compound biosynthesis in plants and shade levels play an important role in the cultivation of medicinal plants. Kaempferia parviflora a popular rhizomatous medicinal plant was investigated for secondary metabolite and plant biomass accumulation in response to shading and cultivar type. Two cultivars KPM (K.parviflora Malysia) and KPT (K.parviflora Thai) were analyzed for growth and secondary metabolite content under four shade levels (0%, 30%, 50%, and 70%). Photosynthetic capability, plant biomass and total flavonoid content were highest both cultivars under 30% shade after 9 months of growth cycle. 0% shade induced stress on plant growth and reduced photosynthetic capability and the flavonoid accumulation in both cultivars. 5,7-dimethoxyflavone (DMF) was used as a chemical marker to quantify secondary metabolite content in K. parviflora cultivars. DMF was greatest in KPM grown under 30% shade. KPT had higher biomass than KPM under 30% but lower DMF content. In conclusion, K. parviflora is a semi shade loving plant suitable to grow under 30% shading for high yield and secondary metabolite production

Application of high resolution melting for detection of induced DNA polymorphism in Curcuma alismatifolia

In order to reveal the induced variations in genomic DNA of mutants, simple sequence repeats (SSR) are used in plant genetics and breeding programs, which are commonly analyzed by fragment size separation using gel electrophoresis. However, post-PCR handling processes are laborious and costly. In addition, gel electrophoresis based methods cannot detect SNPs present in the sequences flanking repeat motif. High resolution melting curve (HRM) analysis is a new technique, which is efficient, accurate, and cost-effective in detecting the sequence differences in polymerase chain reaction (PCR) amplicons, even single nucleotide polymorphisms (SNPs) or insertions or deletions (INDELs). In present study, we used the HRM followed by DNA sequencing to discriminate induced microsatellite polymorphism among irradiated and non-irradiated individuals of Curcuma alismatifolia in third generation (M1V1). The results showed that the combination of HRM with sequence confirmation is a powerful high-throughput, accurate, and reproducible approach to detect induced SSR polymorphism among mutants of C. alismatifolia. For the mutants with SNPs polymorphism present in the flanking region, HRM also gave distinct melting curves, which the gel electrophoresis was not able to detect. In conclusion, it has been approved that HRM as pre-sequencing, efficient, and cost-effective screening method enables rapid SSR polymorphism detection in mutant population of C. alismatifolia

Improvement on rooting quality of Jatropha curcas using indole butyric acid (IBA).

The effects of indole-3-butyric acid (IBA) concentrations and three types of cutting (softwood,semi hardwood and hardwood) on root performance of Jatropha curcas L. cuttings were investigated. Two experiments were conducted where in experiment 1, conducted on July 2007, the hardwood cutting gave the highest mean value for root dry weight (0.2g), number of roots (22) with percentage of rooted cuttings (56%) compared to the one using softwood cutting. 10, 000 mg/L IBA gave the highest mean value for root length (13.6cm), number of roots (28), percentage of rooted cuttings (74%) with root dry weight (0.5g). In experiment 2, conducted on January 2008, the hardwood cutting once again gave the highest mean value for root length (12.1cm) and root dry weight (0.4g). The greatest root number (59) was obtained at 20, 000 mg/L. There was no significant effect on percentage of rooted cuttings, root dry weight, root length and rootball diameter. The histological studies showed that adventitious roots were originated directly from the endodermis. The root primordial started to develop on day 8 and emerged through the epidermis after day 11