eChapters

ABSTRACT

Astudy was conducted to establish the regeneration capacity of pseudobulb segments of a Dendrobium hybrid orchid (D. nobile L. x D. chrysotoxum L.) in vitro on full strength (MS) and half strength (½ MS) Murashige and Skoog medium. Pseudobulb segments having 0.3-0.5 cm length cut from the in vitro maintained hybrid orchid were inoculated on both media supplemented with different concentrations and combinations of NAA, BAP and Kn. On MS medium the pseudobulb segments failed to respond, however, in ½ MS medium the explants responded well. Responding explants were maximum (35%) on the medium ½MS + 0.1 mgl^-1 NAA + 0.5 mgl^-1 BAP. An average of two (2) shoot buds per explant were regenerated on ½ MS + 2.0 mgl^-1Kn and ½ MS + 0.1 mgl^-1 NAA + 1.0 mgl^-1 BAP. The regenerated plantlets grew healthily on subculture after separation from the pseudobulb segments.

ABSTRACT

There has been conscious effort to discover and apply biological pesticides for the control of insect predation. Insecticidal proteins/ genes from Bacillus thuringiensis have been deployed as sprays and through transgenic route for crop protection against insect attack and have been successful in protecting the crop damage and environment pollution. However, impending fear of development of resistance to Bt proteins by insects has prompted search for new insecticidal proteins. In this context we are exploring and analysing components of insect immunity as targets for restricting insect feeding behaviour. Insects encounter several microbes during different stages of growth and development. Incidental entry of these microbes elicits a host defense response, which mainly consists of a phenoloxidase (PO) pathway. The invasion of the microbe is recognized by a specific protein, which activates the PO pathway consisting of prophenoloxidase (PPO) & prophenoloxidase activating enzyme (PPAE). Understanding the mechanism of insect immunity will allow us to discover potential targets for inactivating the mechanism of immune action in insects and make them vulnerable to natural microbial infection.

An agronomically important polyphagous pest, Heliothis armigera (Bollworm) was chosen in the present work for studying the components of insect immunity. H. armigera is the most important insect pest of the developing world accounting for heavy damage on various crops including cotton, vegetables, tobacco, potato, groundnut, chickpea and pigeon pea. We have isolated full-length cDNA encoding prophenoloxidase (PPO) and a partial cDNA encoding PPAE from haemocytes of 5th instar larvae of H. armigera. The open reading frame (ORF) of PPO gene is 2.1 kb, which encodes for a 698 amino acid protein with a molecular mass of 77 kDa. Computer-assisted analysis revealed the presence of 60 amino acid long propeptide at the N terminus of protein and 2 copper binding motifs but no signal peptide was detected. The gene was cloned and expressed in a bacterial expression vector pET43b under the induction of IPTG. The SDS-PAGE analysis showed that the protein is expressing in the supernatant in its native form. The expressed enzyme is catalytically active on 4-Methylcatechol upon activation by cetyl pyridinium chloride (CPC). The regulatory role played enzyme in insect immunity is being examined.

ABSTRACT

Production of cardamom in India has been greatly affected by Cardamom mosaic virus (CdMV). The conventional breeding program to develop resistance is a lengthy process. An alternative approach is to develop transgenic cardamom through introduction and expression of viral sequences in the plant. The coat protein (CP) gene of all the CdMV isolates have been cloned in pGEMT vector and sequenced. Sequence comparison studies of the eight isolates of CdMV in their CP and 3’UTR showed that, Kursupara isolate is highly variable from the rest of the isolates (Jacob et al., 2003). Hence the present study was undertaken to introduce the Kursupara CP gene of CdMV into cardamom plants in order to develop pathogen-derived resistance in cardamom. The CP gene of the Kursupara isolate of the virus was amplified with and without the 3’untranslated region (3’UTR) from the viral clone. These PCR products were cloned into the pXcmkn12 vector and sub cloned in to a plant expression vector (pAHC17) at the BamHI site, under maize ubiquitin promoter. Work is in progress towards the biolistic transformation of cardamom with these constructs.

ABSTRACT

The cry1A genes of Bacillus thuringiensis (Bt) are widely used to engineer lepidopteran insect resistance in crop plants including horticultural crops. Continuous exposure of a single kind of Bt toxin can lead to resistance development in insect pest. Due to the difference in structure and unique insecticidal mechanism, cry2A genes are promising candidates for management of resistance development. Since India is rich in biodiversity and genetic resources, indigenous Bt strains are valuable tool for identification of novel cry genes. The present study describes the cloning of cry2Ab from a new indigenous strain of Bt, 14RI. The presence of cry2Ab gene in Bt strain 14RI was confirmed by PCR with primers specific to its internal region. Primers corresponding to the flaking region of cry2Ab were used for amplification of cry2Ab orf from the Bt strain 14RI. The amplified cry2Ab orf was first cloned into the T/A cloning vector, and then fused to the downstream of the cry2Aa promoter along with its orf1 and orf2 in the Bt shuttle vector pHT1301. Acrystalliferous Bt strain 4Q7 has been transformed with recombinant pHT1301 to express the cry2Ab of Bt strain 14RI.

ABSTRACT

The present study was conducted to screen fungal isolates for chitinolytic activity and to clone full-length endochitinase gene from fungus. Among the ten isolates tested (Trichoderma harzianum 1, 2, 3, Trichoderma koningii, Trichoderma virens, Trichoderma viride, Aspergillus oryzae Metarshizium verrucasia, Bauveria bassiana, Nomuraea releyi), Trichoderma koningii showed higest colloidal chitin hydrolysis when screened in Mandels and Reese (1969) salts supplemented with colloidal chitin as the sole carbon source followed by Aspergillus oryzae. Nomuraea releyi showed least chitinolytic activity. Other isolates were on par with each other. The use of diagnostic primers showed specific amplification of 260 bp in Trichoderma harzianum isolates 1,2 and3, Trichoderma koningii and Trichoderma virens, which confirmed presence of endochitinase gene.

Attempts were made to clone full-length endochitinase gene from isolates showing chitinolytic activity. A unique amplicon of 1.7Kb from Trichoderma virens was cloned into linear pTZ57R/T vector with T over hangs. The confirmation of clones was made through blue/white colony assay, plasmid mini-preparation and PCR amplification of these plasmids, sequencing and BLAST search at NCBI. Among the clones confirmed, pSAV804 was sequenced that showed 98% homology with other reported endochitinase genes from Trichoderma spp at DNA and protein level. 85.7% of the protein is conserved. The ORF of the sequence comprises of 822 bases, which deduces 274 amino acids. The position of primer sequence in the insert and BLAST results confirmed the reverse orientation in the vector. The endochitinase gene now needs to clone into the expression and plant expression vectors for further studies.

Clove bean is christened so because of the resemblance of its thickened pedicel to the cloves of spice grown in isolated pockets of Kerala. This crop is neglected so long and remained unexploited though it has good potential for development. The tender and swollen pedicel of the fruit is used as a delicious vegetable vernacularly known as michi in Hindi and Bengali, garyo in Gujarati, kattuthali in Tamil, gariya in Marathi and nithya vazhuthana in Malayalam.

This vegetable grows from sea level as in Western Coasts of Kerala to an altitude of 1700 m amol in the Himalayas (Kirthikar and Basu 1935). The crop grows in the Gangetic plains and in Deccan hills. It is distributed in warmer parts of South and South East Asia including Upper Myanmar, Nepal, Sri Lanka, China and Japan. (Raizada and Saxena 1978).

3.1. Origin and distribution

• Native to the Moluccas Islands of Indonesia.

• Although Indonesia is the largest producer of cloves, Zanzibar and Madagascar are the major exporters,

• In India, grown in the hilly tracts of Tamil Nadu, Kerala and Karnataka.

3.2. Economic importance

• Clove taste is imparted by eugenol and quantity of pice required is small.

• Pairs well with cinnamon, allspice, vanilla, red wine, basil, onion, citrus peel, star anise, and pepper corns.

Stem-borer: Sahyadrassus malabaricus: Hepialidae

Presence of the pest is understood when chewed tissue is seen at at the col­lar region. The mouth of the tunnel in which the borer feeds show pieces of bark, wood and frass particles held together by silk. The saplings break off at the point of injury. When the main stem is attacked, there is mat-like frass at basal region of stem. Larvae girdle main stem and bores downward killing the tree.

Adult moth is peculiar and hangs vertically down by the support of two pairs of legs. Egg period is for 7-10 days, and larvae live for about 10 months inside the larval tunnels. They pupate for 3-5 weeks.

English name : Clove
Botanical name : Syzygium aromaticum Merr &Perry
Family : Myrtaceae
Chromosome number : 2n = 22
Centre of origin : Indonesia
Clove of commerce is the fully grown but unopened dried flower bud of tree Syzygium aromaticum Merrill and Perry, belonging to the family Myrtaceae. The English name “clove” is derived from the Spanish word clavo or the Latin clavus, both meaning “nail,” referring to the shape of the dried clove bud commonly found in the market. Clove is among the orient’s oldest and most valued spices, known as early as the 1st century BC. It is prized both as a spice and for its essential oil. The chemical composition of clove varies based on agroclimatic conditions and post-harvest processes.
The dried clove bud contains approximately 5.4% moisture, 6.3% protein, 13.2% volatile oil, 15.5% non-volatile ether extract (fat), 11.1% crude fibre, 57.7% carbohydrates, 5.0% mineral matter, and 0.24% ash insoluble in HCl. Additionally, it has 0.7% calcium, 0.11% phosphorus, 0.01% iron, 0.25% sodium, and 1.2% potassium. Its vitamin content includes 0.11 mg of B1, 0.04 mg of B2, 80.9 mg of vitamin C, 175 I.U. of vitamin A, and 1.5 mg of niacin per 100 g, providing a calorific value of 430 calories per 100 g. The volatile oil extracted from clove buds consists of eugenol (80-90%) and caryophyllene (4-8%).

Cluster bean [Cyamopsis tetragonoloba (L.) Taub.] popularly known as guar is a drought hardy, deep-rooted, summer annual legume, grown as feed, fodder, green manure, vegetable and seed in the dry habitats of Rajasthan, Haryana, Gujarat and Punjab and to a limited extent in Uttar Pradesh, Madhya Pradesh and Tamil Nadu. In addition to its major cultivation in India, the crop is grown as a cash crop in different countries like Australia, Brazil and South Africa. The crop is exceptionally known for its higher adaptation towards poor and erratic rains, low inputs and less care. Its other multi uses are soil enrichment in cropping systems, industrial uses, social and dietary uses. These qualities have made it as the most favoured crop of marginal farmers in the arid areas. Being a leguminous annual, its primary use is soil health enrichment through atmospheric nitrogen fixation; on an average basis it is estimated to be  30 kg N ha-1. The young pods of Cluster bean are a source of delicious vegetable from late summer to middle of rainy season. The pods are sweet and can often be cooked as those of Phaseolus bean pods and are a very good source of vitamin A, calcium, iron, phosphorus and ascorbic acid with enriched nutritional value.

ABSTRACT

Albizzia lebbeck is commonly called as “vagai” in Tamil belonging to family Mimosaceae, is a large deciduous tree commonly seen throughout India. Our present aim, was to study the CNS depressant activity of Albizzia lebbeck in wistar albino rats. The bark and leaves of Albizzia lebbeck were shade dried and coarsely powdered. About 500 gm of powder was extracted using petroleum ether, chloroform and alcohol by cold maceration process. The depressant activity was accessed using actophotometer. It was claimed that in indigenous system of medicine the drug has anti-inflammatory, opthalmopathy, leucoderma, leprosy, wounds, ulcers and CNS depressant activity.

7.1. Origin and distribution

• Native to Tropical America, the Amazon Basin.

• Domesticated in Mexico and Central and South America.

• Cultivated in Karnataka, Kerala and Tamil Nadu mainly as intercrop and multi-storey crop with arecanut and coconut from 1970 onwards.

7.2. Economic importance

• Cocoa is a cauliflorus beverage crop.

• Chocolate, hot chocolate, cocoa powder and dry powder are made

• Cocoa butter (the fat) can be extracted.

• Used in Mesoamerican foods including tejate and Mexican drink that also includes maize.

Botanical Name:  Theobroma cacao L. 
Family :   Sterculiaceae
Origin :  Central and South America.
Chromosome No :  2n=20
Type of fruit : Drupe.
Type of Inflorescence : Dichasial (cyme)
Useable Part : Seed 

Cocoa is popularly known as cacao in many cocoa growing nations. Cocoa beans are the source of commercial cocoa. The cocoa products viz., cocoa liquor, cocoa butter, cocoa cake, cocoa powder and cocoa chocolate are widely consumed across the World. Cocoa powder is essentially used as flavour in biscuits, ice cream, dairy drinks and cakes. Apart its use as flavour it is also used in the manufacture of coatings for confectioners or frozen desserts. Cocoa powder is also consumed by the beverage industry for example for the preparation of chocolate milk. Besides the traditional uses in chocolate manufacture and confectionery, cocoa butter is also used in the manufacture of tobacco products, soap and cosmetics. It is also a folk remedy for burns, cough, dry lips, fever, malaria, rheumatism, snakebite and wounds. It is reported to be antiseptic and diuretic. Looking at the industry needs for various purposes, there is a heavy demand for cocoa. At present, the gap between supply and demand in cocoa appears to be more at the national level. To fill the gap, various agro-technologies and crop improvement strategies are to be chalked out, for which the response of the crop to various environmental factors are to be understood. Weather aberrations during the flowering and fruiting result in the final cocoa production. Therefore, it is important to understand the effect of weather on flowering and fruiting pattern of cocoa to minimize the crop losses against the weather abnormalities. Though it is known that cocoa yield is highly variable and sensitive to various weather factors, the studies on crop weather relationships in cocoa and its response to climate change/variability are relatively scant

Cocoa (Theobroma cacao L.) is the third important beverage crop grown for its seeds known as beans, used mainly in chocolate industry. It is the source of cocoa butter and cocoa mass.

Cocoa, Theobroma cacao is an important commercial plantation crop of humid tropics. It was introduced as a mixed crop in India and is cultivated in coconut and arecanut plantations large scale from 1970 onwards. It is grown as an under- storey intercrop with sufficient shade in southern states of India. Tamil Nadu is the major cocoa producing state in India. Some pests of economic importance are described hereunder:

Mealy bugs, Planococcus lilacinus (Ckll.) and P. citri (Pseudococcidae: Hemiptera)

These two species are most prevalent in all cocoa growing tracts of the country. Beside cocoa, it also infests coffee, citrus, guava, mango, etc. The adult female is an oval wingless insect which measures 4mm in length. The body colour is chocolate brown and the dorsal body surface is covered with thick waxy covering (Plate 14g). The male is winged and free living.

3.1. Origin and distribution

• Origin is in South Asia - Malaysia, Pacific.

• In the Pacific, cultivated on islands in Southeast Asia - Philippines, Malaysia, Indonesia.

• In the Indian Ocean, centre of cultivation is southern periphery of India including Sri Lanka, Maldives and Laccadives.

• In India, coconut palms are grown on the entire coastal belt of Kerala, Karnataka and Tamil Nadu followed by Goa, Maharashtra, Andhra Pradesh, and Odisha.

• Kerala, Tamil Nadu, Karnataka and Andhra Pradesh are the major coconut producing states accounting for more than 90% of area and production

1) Bud Rot
Diagnostic Symptoms
• Severe on young palms.
• Yellowish green discoloration of the heart leaf or crown leaf.
• The basal tissues of the leaf rot quickly and can be easily separated from the crown.
• Spindle withers and droop down.
• Older leaves develop irregular, water soaked spots which are sunken in nature.
• The leaves and sheath in the central spindle fall off leaving an outer whorl of green leaves.
• The withered central shoot can be pulled out very easily from the crown.
• The central crown may rot and in few months the tree may wilt.
• Young nuts fail to mature and fall (Fig.1).

Botanical Name : Cocus nucifera Linn. 
Family : Palmae
Origin : South East Asia and Malaysia. 
Chromosome No :  2n = 32
Type of fruit : Drupe.
Type of Inflorescence : Spadix
Useable Part : Kernel

The Coconut palm, also known as the Cocos Nucifera L., is one of the most fascinating and beautiful palms in the world. The coconut is believed to have originated in southeast Asia (Indonesia, Malaysia, Philippines) or Micronesia. Coconut has been cultivated in India since ages and plays an important role in social, economic and cultural activities of the people. The palm is amenable to both plantation and homestead management and it can be either a major crop or a minor one in a homestead garden of mixed crops. While responding favourably to scientific management, the palm also tolerates negligent farming to a certain extent. Thus, it can adapt to the divergent farming situations and management practices that are prevalent in different agro-climatic regions. The coconut palm is usually found near the sea on sandy beaches where it can tolerate salt spray and brackish soils. It is also grown under different soil types such as loamy, laterite, coastal sandy, alluvial, clayey and reclaimed soils of the marshy low lands. The ideal soil conditions for better growth and performance of the
palm are proper drainage, good water holding capacity, and presence of water table within three metres and absence of rock or any hard substratum within two meters of the surface. The coconut palm can also grow well inland, within altitudinal limit of 600 m to 1000 m in the Tropics. It requires an equatorial climate with high humidity. A year-round warm and humid climate favours thegrowth of coconut. The palm does not withstand prolonged spells of extreme weather/climate variations under rain fed conditions. A welldistributed rainfall of 1300–2300 mm per annum is preferred. It is known as a coastal tree since it is grown along the Coasts and Islands and does not tolerate high diurnal temperature range, that is the difference between the maximum and minimum temperatures.