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ABSTRACT: Curculin, a sweet protein found in Curculigo latifolia fruit has great potential for the pharmaceutical industry. This protein interestingly has been found to have both sweet taste and taste-modifying capacities comparable with other natural sweeteners. According to our knowledge this is the first reported case on the isolation of microsatellite loci in this genus. Hence, the current development of microsatellite markers for C. latifolia will facilitate future population genetic studies and breeding programs for this valuable plant. In this study 11 microsatellite markers were developed using 3' and 5' ISSR markers. The primers were tested on 27 accessions from all states of Peninsular Malaysia. The number of alleles per locus ranged from three to seven, with allele size ranging from 141 to 306 bp. The observed and expected heterozygosity ranged between 0.00-0.65 and 0.38-0.79, respectively. The polymorphic information content ranged from 0.35 to 0.74 and the Shannon's information index ranged from 0.82 to 1.57. These developed polymorphic microsatellites were used for constructing a dendrogram by unweighted pair group method with arithmetic mean cluster analysis using the Dice's similarity coefficient. Accessions association according to their geographical origin was observed. Based on characteristics of isolated microsatellites for C. latifolia accessions all genotype can be distinguished using these 11 microsatellite markers. These polymorphic markers could also be applied to studies on uniformity determination and somaclonal variation of tissue culture plantlets, varieties identification, genetic diversity, analysis of phylogenetic relationship, genetic linkage maps and quantitative trait loci in C. latifolia.
Molecular Biology Reports 06/2012; 39(11):9869-77. · 2.93 Impact Factor
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ABSTRACT: In recent years Jatropha curcas has drawn the world’s attention as it
has the potential to replace fossil fuel as biodiesel. However, the biggest setback in Jatropha cultivation
in Malaysia is the low percentage of fruit set and the high ratio of male to female flowers. In order to
further understand the flowering and fruit characteristics of Jatropha, floral and fruit development
timeline is needed in order to develop solutions for the problems in low fruit set. Approach: This
study described the flowering behaviour of Jatropha curcas cultivated under Malaysia and 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). Results: Jatropha is monoecious and produces individual flowers in a dichasial cyme. Each
Jatropha inflorescence has at least six compound cymes. Male flower anthesis started the earliest at
12.00 am and again at 6.10-6.46 am. Female flower anthesis commenced at 6.35-8.25 am. Male
flowers opened for a period of 8-11 days, while female flowers opened for only 3-4 days. The reading
of the male to 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 bears fruits profusely in January, May and August 2009. Development of the floral
meristem consists of three stages that include a vegetative stage, transition from vegetative to floral
stage and the development of flower parts. The meristem was in the transition stage at day 6. All
Sepals and a petal were developed at day 18 but there was no presence of reproductive organs
developing at this stage. Flower and fruit development takes approximately 3 months to complete the
cycle from the initiated floral bud stage until fruit maturity. Conclusion: Continuous flowering and the
incidents where flowering terminated in the middle of the flowering period were factors believed to
cause the wide range of fruit ripening times recorded. The problem of small number of fruits produced
in Jatropha curcas is mainly caused by the small number of pistillate flowers present in each
inflorescence that range from 0 to 10 flowers in the same inflorescence. Jatropha could have two to
four cyclical fruiting peaks in Malaysia.
American Journal of Agricultural and Biological Science 01/2011; 6(1):142-147.
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ABSTRACT: Huanglongbing (HLB) also known as citrus greening disease is a fastidious phloem-inhabiting bacterium in the genus Candidatus Liberibacter. Using universal primers, the 16S ribosomal DNA sequence of three strains of the bacterium were obtained by PCR. However there is very little information on seed transmission and HLB pathogen movement to find a way for control or reduce the severity of HLB on the field. The study was conducted to detect HLB pathogen in seeds of Citrus, to determine pathogen movement in citrus seedling after infection and to detect the HLB pathogen in citrus roots. Approach: Seeds of Citrus reticulata cv. Limau Madu were collected from infected orchard and were germinated in screenhouse condition. The seeds of Citrus reticlata cv. L. Madu were planted in screenhouse too for HLB pathogen movement and HLB detection in roots. The seedlings were inoculated using infected grafting methods. Results: HLB was not amplified in new seedlings after germination. HLB moved slowly reaching up to 1.5 cm after 2 weeks, 1.5-4.5 cm after eight weeks and detected on 4.5-9 cm after 14 weeks below the grafting area. HLB was also detected up to 9-15 cm after 16 weeks, 15-24 cm after twenty weeks, 24-28.5 cm after 22 weeks and 28.5-30 cm after 24 weeks below the grafting area. Conclusion: Base on conventional PCR test, HLB disease in citrus is not seed borne and it can reach to the roots 26 weeks after inoculation.
American Journal of Applied Sciences. 01/2009;
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ABSTRACT: Problem statement: Huanglongbing (HLB) is a phloem limited disease in citrus caused by a fastidious bacterium called ‘Candidatus Liberibacter’ found in Africa, Asia and United States of America (USA). HLB can severely reduce vigor and yield or kill all citrus trees within 5 years. There is a need to screen and identify suitable rootstock for propagation of clean plan materials for citrus in the tropics. This study was conducted to detect the presence of HLB on 18 selected citrus species and to categorize the level of infection and susceptibility of citrus species to HLB. Approach: Eighteen citrus species were assessed for susceptibility to HLB by graft transmission from source infection (Citrus reticulata). Results HLB was detected in 15 species 6 months after grafting using PCR test. Conclusion: The species could be categorized in five groups: Severe group (72-58% severity) which includes C. reticulata, C. sinensis, C. reshni cv. cleopatra, moderate group (50- 41% severity) includes Fortunella sp. cv. Kasturi Chinai, C. macrophylla, C. microcarpa, mild group (25-17% severity) which included C. medica, C. aurantifolia, Citrus sp. (natural biotype), C. jambhiri. The tolerant group which did not show any HLB symptoms but tested positive by PCR test includes C. aurantium and C. aurantifolia. The resistant groups which include C. grandis cv. Limau Bali, C. hysterix and Citrus sp. cv. Limau Tembikai showed no symptoms and were tested negative for HLB.
American Journal of Agricultural and Biological Science. 01/2009;
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ABSTRACT: Abstract: Problem statement: Huanglongbing (HLB) is a phloem limited disease in citrus caused by
a fastidious bacterium called ‘Candidatus Liberibacter’ found in Africa, Asia and United States of
America (USA). HLB can severely reduce vigor and yield or kill all citrus trees within 5 years. There
is a need to screen and identify suitable rootstock for propagation of clean plan materials for citrus in
the tropics. This study was conducted to detect the presence of HLB on 18 selected citrus species and
to categorize the level of infection and susceptibility of citrus species to HLB. Approach: Eighteen
citrus species were assessed for susceptibility to HLB by graft transmission from source infection
(Citrus reticulata). Results HLB was detected in 15 species 6 months after grafting using PCR test.
Conclusion: The species could be categorized in five groups: Severe group (72-58% severity) which
includes C. reticulata, C. sinensis, C. reshni cv. cleopatra, moderate group (50- 41% severity) includes
Fortunella sp. cv. Kasturi Chinai, C. macrophylla, C. microcarpa, mild group (25-17% severity) which
included C. medica, C. aurantifolia, Citrus sp. (natural biotype), C. jambhiri. The tolerant group which
did not show any HLB symptoms but tested positive by PCR test includes C. aurantium and
C. aurantifolia. The resistant groups which include C. grandis cv. Limau Bali, C. hysterix and Citrus
sp. cv. Limau Tembikai showed no symptoms and were tested negative for HLB.
American Journal of Agricultural and Biological Science 01/2009; 4((1)):338.
