Anitha Karun

Accumulation of phenylpropanoid derivatives in chitosan-induced cell suspension culture of Cocos nucifera.

Chitosan-induced elicitation responses of dark-incubated Cocos nucifera (coconut) endosperm cell suspension cultures led to the rapid formation of phenylpropanoid derivatives, which essentially mimics the defense-induced biochemical changes in coconut palm as observed under in vivo conditions. An enhanced accumulation of p-hydroxybenzoic acid as the major wall-bound phenolics was evident. This was followed by p-coumaric acid and ferulic acid. Along with enhanced peroxidases activities in elicited lines, the increase in activities of the early phenylpropanoid pathway enzymes such as, phenylalanine ammonia lyase (PAL), p-coumaroyl-CoA ligase (4CL) and p-hydroxybenzaldehyde dehydrogenase (HBD) in elicited cell cultures were also observed. Furthermore, supplementation of specific inhibitors of PAL, C4H and 4CL in elicited cell cultures led to suppressed accumulation of p-hydroxybenzoic acid, which opens up interesting questions regarding the probable route of the biosynthesis of this phenolic acid in C. nucifera.

Scope of novel and rare bulbiferous coconut palms (Cocos nucifera L.)

A naturally occurring, rare bulbiferous coconut palm was identified at the Central Plantation Crops Research Institute, Regional Station, Vittal in Karnataka State, India, among West Coast Tall population. The palm produces only bulbil shoots in leaf axils in place of normal inflorescence. The identified palm happened to be twins in which one member was more vigorous than the other, but both of them produced only bulbil shoots instead of floral parts. Morphological and molecular studies on these palms revealed the main palm and their bulbil progenies are genetically uniform. The genetic uniformity of the twin mother palms and their bulbil progenies was confirmed through microsatellite analysis using 10 polymorphic SSR primer pairs specific to coconut and has been well demonstrated to differentiate coconut cultivars. The primary and secondary bulbil shoots were found to be capable of growing into independent plants making it possible to use them as propagules to develop a homogeneous clonal population hitherto unavailable in coconut. The bulbils showed axillary growth in 6–12th leaf axil which further again develop as secondary bulbils indicating the complete vegetative state of the palm. Comparison of shoot apices of a normal seedling with bulbil shoot revealed variation in cell growth pattern. Conservation of bulbiferous palms as a unique genetic resource needs to be taken up to utilize these rare sources for future breeding programmes, provided their seed-fertility can be restored.

Development of a SCoT-derived SCAR marker associated with tall-type palm trait in arecanut and its utilization in hybrid (dwarf x tall) authentication

Arecanut cultivars are generally tall, which is a major constraint in arecanut cultivation. High yielding tall cultivars have been crossed with natural dwarf mutant, Hirehalli Dwarf (HD) and hybrids have been developed and released for commercial cultivation. It is very difficult to distinguish selfed progenies of the female mother palm in the nursery stage using morphological traits. Start Codon Targeted (SCoT) primers were used to screen tall cultivars of arecanut and HD. One of the primers, SCoT11, produced an amplicon of around 1300 bp band, which was present in all the tall cultivars, but was absent in the dwarf accession. A SCAR marker, capable of distinguishing tall/dwarf trait in arecanut, was also developed and validated, which could ensure supply of genuine hybrid planting material to the farming community.

Characterization of Annur and Bedakam Ecotypes of Coconut from Kerala State, India, Using Microsatellite Markers

The coconut palm is versatile in its adaptability to a wide range of soil and climatic conditions. A long history of its cultivation has resulted in development of many ecotypes, which are adapted to various agro-eco factors prevalent in a particular region. These ecotypes usually are known by the location where they are grown. It is important to explore such adaptation in the coconut population for better utilization of these ecotypes in coconut breeding programs. The aim of the present study was to identify the genetic diversity of the Bedakam and Annur ecotypes of coconut and compare these ecotypes with predominant West Coast Tall (WCT) populations, from which they are presumed to have been derived, using microsatellite markers. All the 17 microsatellite markers used in the study revealed 100% polymorphism. The clustering analysis showed that Annur and Bedakam ecotypes were two separate and distinct populations compared to WCT. It was also evident from the clustering that Annur ecotype was closer to WCT than Bedakam ecotype.

A database for coconut crop improvement

Coconut crop improvement requires a number of biotechnology and bioinformatics tools. A database containing information on CG (coconut germplasm), CCI (coconut cultivar identification), CD (coconut disease), MIFSPC (microbial information systems in plantation crops) and VO (vegetable oils) is described. The database was developed using MySQL and PostgreSQL running in Linux operating system. The database interface is developed in PHP, HTML and JAVA. Availability http://www.bioinfcpcri.org

Transcriptome sequencing and de novo assembly in arecanut, Areca catechu L elucidates the secondary metabolite pathway genes

Highlights • De novo assembly of arecanut transcriptome unfolds the genes involved in carotenoids and alkaloids biosynthetic pathways.• High level of transcripts for carotenoid biosynthetic pathway genes implies arecanut as a potential source of carotenoids.• First report on arecanut transcriptome reveals microsatellites in areca transcriptome sequence.