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Volume 2 Number 1 & 2 2008 
CONTENTS AND ABSTRACTS
Number 1
Ji Gang Kim (Korea) Quality Maintenance and Food Safety of Fresh-cut Produce in Korea (pp 1-6)
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ABSTRACT
Invited Mini-Review: In Korea, the fresh-cut produce market reached approximately US $1.1 billion in 2006. The increase in consumption of fresh-cut produce was brought about by an expanded number of retail markets over the last 5 years. As retail consumption increases, the Korean fresh-cut industry’s challenge to ensure food safety and quality likewise increases. Researches pertaining to fresh-cut processing technology have focused on mainly delaying quality changes and inhibiting microbial activities. Current techniques that retard browning are mainly exposure to low temperature, peeling by hydraulic means, and vacuum packaging. Vacuum packaging induces too high CO2 and low O2 levels which may cause off-odor development and growth of anaerobic bacteria during retail distribution. Modified atmosphere (MA) packaging using films with different oxygen transmission rates (OTR), including porous films have just started for application to fresh-cut produce. Chlorine is still widely used as a sanitizer in reducing microbial contamination. However, the Korean fresh-cut industry is not only concerned about searching for more effective sanitizers but also environmental friendly washing methods. Electrolyzed, ozonated, and hot water, or combinations of known washing techniques have been applied to the fresh-cut industry. Further practical research on washing and packaging technology is required to improve quality and food safety of fresh-cut products.
Ravindra B. Malabadi (Canada/India), Jaime A. Teixeira da Silva (Japan), K. Nataraja (India) Agrobacterium tumefaciens-Mediated Genetic Transformation of Pinus kesiya Royle ex Gord (Khasi Pine) (pp 7-14)
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Original Research Paper: This study highlights, for first time, an Agrobacterium-mediated gene transfer method for the genetic improvement of Pinus kesiya. The genetic transformation of P. kesiya has been limited by difficulty in selection efficiencies and a low transformation frequency. Embryogenic cultures were established from zygotic embryos according to our previous protocol (Malabadi et al. 2005). During transformation events, rapidly growing embryogenic tissue of three genotypes were co-cultivated with disarmed A. tumefaciens strain EHA105 fused with a binary vector pBI121, which contains the neomycin phosphotransferase II (nptII) gene providing kanamycin resistance as a selectable marker and the β-glucuronidase (uidA) reportergene, was used in the transformation studies. All the transgenic lines exhibited very low maturation potential compared to the control. GUS activity was used to monitor transient expression of the uidAgene and to further test lines selected on kanamycin-containing medium. The integration of one of the transgenes, nptII, was confirmed by PCR followed by Southern and Northern blot analyses. Agrobacterium-mediated gene transfer was found to be a very useful technique for large-scale generation of transgenic P. kesiya, and may prove useful for other recalcitrant conifer species.
Gulshan Mahajan, T. S. Bharaj (India) Yield and Water Productivity of Rice Cultivars as Influenced by Transplanting Dates and Seedling Age in Irrigated Semi-Arid Subtropical Environment (pp 15-19)
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Original Research Paper: In order to study water and crop productivity in rice, a field experiment was conducted to see the effect of rice cultivars in relation to age of seedling and transplanting dates for a period of two years at Punjab Agricultural University, Ludhiana, India. The study revealed that shifting the date of transplanting from the 15th June to the 5th July resulted in a saving of 212 mm irrigation water without compromising rice yield. Crop water productivity was not significantly influenced by seedling age. Grain yield, however, declined significantly when the crop was transplanted with 60-days-old seedlings rather than 30 or 45-days-old seedlings. Cultivar ‘PAU-201’ showed the highest yield among all the cultivars and the mean yield increased to the extent of 17.8, 11.5 and 12%, compared with cvs. ‘PR-115’, ‘PR-116’ and ‘PR-118’ respectively. The early maturing cultivar ‘PR-115’ saved 19.5, 22.4 and 21.9% more irrigation water than cvs. ‘PR-116’, ‘PR-118’ and ‘‘PAU-201’’, respectively. Crop water productivity was highest in cv. ‘PAU-201’ (33.73 Kg/ha/cm) transplanted on 5th July followed by cv. ‘PR-115’ (33.59 Kg/ha/cm). When transplanted on the 15th June, crop water productivity was highest in early maturing cv. ‘PR-115’ (32.89 Kg/ha/cm) followed by cv. ‘PAU-201’ (29.34 Kg/ha/cm). Crop water productivity was significantly less in cv. ‘PR-116’ and late maturing cv. ‘PR-118’ than in cvs. ‘PR-115’ and ‘PAU-201’ on all transplanting dates.
P. Narayanaswamy, H.S. Ravi (India), Luke Simon (UK/India), Y. Pampanna (India) Morphological Traits and DNA Fingerprinting among Traditional and Commercial Indian Pomegranate (Punica granatum L.) Cultivars (pp 20-26)
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Original Research Paper: In the present study, the genetic relationships among forty six genotypes of pomegranate (Punica granatum L.) obtained from diverse locations of India were analysed by morphological and RAPD (Randomly Amplified Polymorphic DNA) markers. The morphological data was obtained for their reproductive characters. PCR-amplifiable DNA was isolated using the CTAB method and 123 amplified fragments were obtained using 8 random primers. The genetic dissimilarity matrix which was calculated based on Euclidian Distances revealed a maximum genetic distance of 22% between genotypes, ‘Alah’ and ‘Gulsha Red’ and the minimum genetic distance (2%) was between the genotypes ‘Shirin Anar’ and ‘Kazakaki Anar’ and ‘Gulsha Red’ and ‘Kalishirin’. The Ward’s method of cluster analysis grouped all the individuals on the dendrogram into two major clusters ‘A’ and ‘B’ at 54 linkage distance units with two sub-clusters each. Sub-cluster ‘A1’ consisted of 21 genotypes in two groups with very hard seed, low Total Soluble Sugar (TSS) value and few fruits in group I and genotypes with high TSS value and many fruits in group II. Sub-cluster ‘A2’ consisted of nine genotypes predominantly with few fruits with very hard seeds. Cluster B with 16 genotypes comprised of morphological characters predominantly showing light aril colour, soft seeds, low acidity, high TSS value and higher fruit yield. The present study showed low genetic diversity among the cultivars of pomegranate. RAPD combined with morphological analysis proved to be a quick, simple and significant testing method to assess genetic diversity among pomegranate.
Kamlesh Kanwar, Vinay Kumar, Raj Deepika (India) Assessment of Wild and Cultivated Punica granatum L. using Random Amplified Polymorphic DNA (RAPD) Markers (pp 27-30)
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Original Research Paper: In Punica granatum L. genetic variability was investigated among wild and five pomegranate cultivars (‘Ganesh’, ‘G-137’, ‘Mridula’, ‘Musket’, ‘Kandhari Kabuli’) growing in Western Himalaya, India. Random amplified polymorphic DNA analysis was studied using 21 arbitary decamer primers to observe genetic homogenity/polymorphism among wild and cultivated genotypes. The percentage of polymorphism was 76.26%. Jaccard’s coefficient and UPGMA-based analysis showed 0.62 to 0.83 similarities among these genotypes. In the dendrogram, there was one main cluster and 4 subclusters. Wild pomegranate was found to be distant from the cultivars and grouped alone at the 69% similarity level, while Kandhari Kabuli and Mridula showed maximum similarity (0.83). Musket and Ganesh formed one cluster, while was G-137 clustered alone. The lowest value (0.62) was found between Ganesh and G-137, whereas the maximum value (0.83) was found between Kandhari Kabuli and Musket, suggesting a common origin of all cultivars from the same parent.
B. Purushotham, P. Narayanaswamy (India), Luke Simon (UK/India), S. Shyamalamma, Mahabaleshwar Hegde, B. Jaypalgowdu (India) Genetic Relationship between Cultivars of Areca Nut (Areca catechu L.) Determined by RAPD (pp 31-35)
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Original Research Paper: In the present studies, genetic relationships among eleven cultivars of Areca nut (Areca catechu L.) obtained from Western Ghats regions of India were analysed using RAPD markers. PCR-amplifiable DNA was isolated using the CTAB method and 146 amplified fragments were obtained using 19 random primers. The genetic dissimilarity matrix, which was calculated based on Squared Euclidian Distances, revealed a maximum genetic distance of 47% between cultivars, ‘Mohit Nagar Interse’ and ‘Mohit Nagar’ and the minimum genetic distance (22%) was between the genotypes ‘Maidan Local’ and ‘Sree Mangala’. The Ward’s method of cluster analysis grouped all the individuals on a dendrogram into two major clusters ‘A’ and ‘B’ at 29 linkage distances with two sub-clusters in cluster ‘A’. The sub-cluster ‘A1’ consisted of nine cultivars in two minor clusters ‘A1a’ and ‘A1b’ linked at 27 distances. The sub-cluster ‘A2’ consisted of one cultivar ‘Sumangala’ linked with ‘A1’ at 28 linkage distance. The cluster ‘B’ consisted of one cultivar ‘Mohit Nagar’. The present study showed moderate genetic diversity among the cultivars of Areca nut. The RAPD analysis proved to be a quick, simple and significant testing method to assess genetic diversity among Areca nut populations studied.
K. R. Raghu Prakash, L. Prasanthi, M. Reddy Sekhar (India) Genetic Variability Studies for Seed Yield, Physiological and Quality Attributes in Guar (Cyamopsis tetragonaloba (L.) Taub.) (pp 36-38)
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Original Research Paper: Study of genetic parameters in fifty genotypes of Guar collected from Rajasthan, Gujarat, Haryana and Karnataka revealed high estimates of variation for number of pods per plant, harvest index, seed yield per plant, leaf area index at 50 days after sowing, number of branches per plant and number of clusters per plant. High heritability coupled with genetic advance as percent of mean was observed for the characters viz., number of pods per plant, seed yield per plant, leaf area index at 50 days after sowing, number of branches per plant, harvest index, number of clusters per plant, plant height, number of pods per cluster, days to maturity, specific leaf area at 40 days after sowing and viscosity indicating that simple selection program would be effective for genetic improvement of Guar.
Selvakumar Veluchamy (India/USA), Anbudurai PR (India) Stimulation of Micropropagation of the Medicinal Plant Aristolochia indica L. through Nodal Explants by Adenine Sulphate (pp 39-41)
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Original Research Paper: An efficient protocol for in vitro propagation of the medicinal plant Aristolochia indica L. (Aristolochiaceae) using nodal explants is presented. Kinetin (KN), gibberellic acid (GA3), benzyl adenine (BA) and adenine sulphate (AdS) were used individually as well as in combination (KN+GA3, KN+BA and KN+AdS) with 2.46 μM indole-3-butyric acid (IBA) incorporated in basal Murashige and Skoog (1962) medium. Shoot proliferation was promoted by AdS (27.1 µM) alone and also in combination with other plant growth regulators (PGRs). Compared to other combinations, KN (23.25 µM) and AdS (13.5 µM) evoked a high frequency of bud break. IBA resulted in enhanced root formation, while the inclusion of IAA rooting was induced on shoots with intervening callus formation at the basal end. Using our protocol, from one twig of A. indica (10 responsive nodal explants), within a period of three months, 10-12 plantlets could be raised with 80% transplantation success.
Number 2
Xiao-qiong Zhu, Li-yun Guo, Xiao-yu Chen (China) Diseases of Peach and Nectarine in China (pp 42-49)
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Invited Review: Prunus persica originated from China, where it has been cultivated for more than 3,000 years. Many diseases on peach and nectarine, both infectious and non-infectious, have been identified in China. Leaf curl, brown rot, anthracnose, gummosis, Leucostoma canker, scab, bacterial spot and crown gall are among the common ones. Tobacco mosaic virus, Prunus necrosis ring spot virus, Prune dwarf virus, Apple chlorotic leaf spot virus and Peach latent mosaic viroid have also been detected in China. The commonly used chemicals for disease control on peach and nectarine are bordeaux mixture, lime sulfur, mancozeb, carbendazim, and thiophanate-methyl. With increasing living standard, the consumer demand for higher quality and safer fruit is increasing, and more and more effort has been put into search for effective biocontrol agents and active ingredients in herbal extracts.
Jing-Ze Zhang (China) Anthracnose of Persimmon Caused by Colletotrichum gloeosporioides in China (pp 50-54)
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Invited Mini-Review: Persimmon (Diospyros kaki Thunb.) is native to China and has been widely cultivated for a long time in China. Colletotrichum gloeosporioides is the major pathogen of persimmon crop in almost all areas where it is grown extensively, causing economically important losses. C. gloeosporioides may overwinter as mycelium in or on diseased tissues of a tree. Conidia are water-borne and spread by splashed rain so infection is usually highest during the wettest periods of the growing season. C. gloeosporioides exhibits an infection strategy of intracellular colonization in the infection process and its infection vesicles and primary hyphae are surrounded by an interfacial matrix that separates the fungal cell wall from the invaginated host plasma membrane. Current management strategies for this fungus comprise the exploitation of cultivar resistance, and cultural and chemical means. This review focuses on some progress made in China, and also describes our own work on the symptoms, origin of inoculum and hemibiotrophic pathogen, C. gloeosporioides on persimmon.
Raj Shekhar Misra, Kamal Sharma, Ajay Kumar Mishra (India) Phytophthora Leaf Blight of Taro (Colocasia esculenta) – A Review (pp 55-63)
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Review: Taro (Colocasia esculenta (L.) Schott.)is an important tropical tuber crop for millions of people in developing countries. Leaf blight caused by Phytophthora colocasiae Rac. is the most destructive disease of taro causing a 25-50% loss in yield. Besides, the pathogen also causes the serious post-harvest decay of corms. Both A1 and A2 mating types have been reported and it is believed that the fungus originated from Hainan Island in Asia. The existence of races of P. colocasiae is not known. The pathogen is reported to survive inside the tubers during the off-season. Collateral hosts also play an important role in the perennation of the pathogen. Secondary spread is through sporangia and zoospores, which are shed in water but not in wind and are carried by splash between plants and plantings. It has been found that Colocasia blight epidemic occurs when night and day temperatures range between 20-22 and 25-28°C, respectively with a relative humidity of 65% during the day and 100% at night and accompanied by overcast, rainy weather. Resistant cultivars have been identified in India, which can be used in breeding resistance. Copper and metalaxyl fungicides have proved to be very effective in controlling leaf blight. More in-depth studies are required to find out the existence of races, if any, of P. colocasiae, survival, biology and ecology of pathogen, a disease-forecasting system, breeding for disease resistance and disease management practices.
Natalja Ryabushkina, Nadejda Gemedjieva (Kazakhstan), Mozaina Kobaisy, Charles L. Cantrell (USA) Brief Review of Kazakhstan Flora and Use of its Wild Species (pp 64-71)
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Review: Approximately 15% of the 161 families of the Kazakhstan flora account for about 75% of the 1118 genera and more than 80% of the >6000 plant species. The sum of the species in the Tamaricaceae, Alliaceae, Polygonaceae, Chenopodiaceae, Caryophyllaceae, Brassicaceae, Zygophyllaceae and Ranunculaceae comprise about 15% of the total Kazakhstan flora and represent a marked part of their corresponding families’ representatives of the world flora. A search of the scientific literature revealed uses associated with representatives from at least 120 families of Kazakhstan’s flora and more than 50 different kinds of biological activity, including use in medicine, food, fodder, essential oils, as tanning or dying agents or in rubber production. In this review, we provided an analysis of the distribution of biological activity among different families and try to outline the representative Kazakhstan flora that should be the subject of more thorough investigations.
Anees Amin (Pakistan), Muhammad Azim Khan (Canada), Gul Hassan, Khan Bahadar Marwat, Haroon Rashid, Khalid Nawab (Pakistan) Weed Control Efficacy and Economics of Pre-emergence Herbicides in Maize (Zea mays L.) (pp 72-75)
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Original Research Paper: A field study was conducted to evaluate the efficacy and economics of different pre-emergence herbicides in maize var. Azam. A randomized complete block design, having four replications was used in the experiment. The treatments were: 1) Stomp 330 E (pendimethalin) at 3.75 L ha-1, 2) Dual Gold 960 EC (s-metolachlor) at 2 L ha-1, 3) Primextra Gold 720 SC (s-metolachlor + atrazine) at 0.98 L ha-1, 4) Atrazine 38 SC (atrazine) at 1 L ha-1, 5) hand weeding and 6) weedy check for comparison. The major weeds infesting the experimental field were Cyperus rotundus, Sorghum halepense, Echinochloa crus-galli, Digitaria sanguinalis, Portulaca oleracea and Digeria muricata. Weed density, weed biomass, plant height, cob length, kernels cob-1, 500-kernel weight, and grain yield were significantly affected by all the herbicidal treatments. Primextra gold greatly suppressed weed density and dry biomass 25 and 75 days after sowing (DAS) and proved to be the most efficient in controlling weeds. Maximum grain yield (2.84 t ha-1) was recorded in Primextra gold 720 SC while minimum grain yield (1.94 t ha-1) was recorded in weedy check. Weed control treatments increased grain yield and yield-related traits of maize as compared to weedy check. Overall, Primextra gold proved more economical by giving maximum net profit.
Jagdish Chandra Ghildiyal, Prem Lal Uniyal (India) Pattern of Bryophyte Richness in Relation to Landscape Features (pp 76-79)
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Original Research Paper: The bryophyte communities in the Rishikesh area, India were analyzed with respect to species diversity, frequency, life strategies and adaptation. The adaptive trends and life strategies were generally subjected to different types of habitats in a zone of disturbances. The prominent life strategies were colonist and shuttle forms which were found to be in frequently disturbed sites. In sub-humid communities colonists with high asexual reproduction are prominent. The analysis of life forms, life strategy and morphological adaptation indicate that common adaptive trends arise convergently but independently in unrelated taxa when they evolve under similar habitat conditions. This also provides insight into the establishment of species, habitat maintenance and dispersal strategy and highlights the most important habitat type for bryophyte species richness in various types of landscapes in term of climatic and land use while discerning the most influential factor for distribution of species in these habitats.
Tukaram D. Nikam, Mohammad A. Ebrahimi, Ravisha S. Sawant, Suresh Jagtap, Pradip P. Patil (India) Ecorestoration of Ceropegia odorata Hook and C. maccannii Ansari, Endangered Asclepiads, by Micropropagation (pp 80-83)
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Original Research Paper: An in vitro propagation system based on axillary shoot proliferation was developed for the ecorestoration of threatened medicinal and starchy edible tuber-producing asclepiads Ceropegia odorata Hook and C. maccannii Ansari. Shoot multiplication was induced by different concentrations of benzylamino purine (BA) and kinetin (Kin) (0.0 to 20.0 µM) added separately. In both C. maccannii (5.2 ± 0.8 shoots per explant) and C. odorata (6.1 ± 0.7 shoots per explant), maximum shoots formed when nodal segments of in vitro-raised shoots were cultured on full strength Murashige and Skoog (MS) basal medium fortified with 7.5 µM BA. Inclusion of indoleacetic acid (IAA) (1.0–2.5 µM), naphthaleneacetic acid (NAA) (1.0–2.5 µM) and 2,4-dichlorophenoxyacetic acid (2,4-D) (0.5–1.0 µM) in nutrient media counteracted the shoot induction effect caused by BA (7.5 µM) or Kin (7.5 µM). Shoots rooted most successfully on half-strength liquid medium fortified with 5% sucrose and 0.5 µM indolebutyric acid (IBA). Micropropagated plantlets were transplanted into soil and about 80% of the plantlets survived which were morphologically identical to donor plants. The regeneration protocol developed in this study provides a basis for germplasm conservation and utilization of these plant species.
Vinay Kumar, Varsha Shriram, Tukaram D. Nikam, Polavarapu B. Kavi Kishor, Narendra Jawali, Mahadeo G. Shitole (India) Assessment of Tissue Culture and Antibiotic Selection Parameters Useful for Transformation of an Important Indica Rice Genotype Karjat-3 (pp 84-87)
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Original Research Paper: We assessed the tissue culture conditions and antibiotic selection of embryogenic callus and report an efficient, simple and reproducible system for mature embryo-derived embryogenic callus induction, its proliferation, its sensitivity against antibiotics such as hygromycin B and cefotaxime, and indirect plant regeneration through callus in a high-yielding, early maturity indica rice genotype ‘Karjat-3’. Whitish-yellow, compact, hard and globular embryogenic callus was produced on MS media fortified with 2 mg/l 2,4-dichlorophenoxyacetic acid, 500 mg/l proline, 500 mg/l casein hydrolysate. The threshold limit for survival of callus was observed under hygromycin B (20 mg/l) and cefotaxime (250 mg/l). Multiple shoots (4-5 shoots per callus) were achieved on MS media supplemented with 4 mg/l kinetin and 1 mg/l α-naphthaleneacetic acid. These Microshoots were rooted on half strength MS media without any plant growth regulator and these rooted plantlets were transferred to soil after gradual acclimatization. The present study may be useful for genetic transformation of this indica rice genotype.
Parul Mathur, Manohar S. Rao, Sunil D. Purohit (India) Genetic Stability in Micro-clones of Celastrus paniculatus Willd. Derived from Different Pathways of Micropropagation as Revealed by RAPD Profiles (pp 88-91)
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Original Research Paper: Micro-clones of Celastrus paniculatus Willd. derived from two different micropropagation pathways (axillary branching and adventitious regeneration) were subjected to molecular screening using random amplified polymorphic DNA (RAPD) markers. Of 20 decamer primers used, amplification products were obtained with 11 primers only. The number of bands varied from 5 to 12. Irrespective of the micropropagation pathway, no variability could be detected in the regenerants suggesting that both pathways are reliable and could be used for large-scale production of this plant.
S. Sree Lekha, Santha V. Pillai (India) SSR Marker Variability in a Set of Indian Cultivars from a Typical Cassava-Growing Area (pp 92-96)
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Original Research Paper: Cassava (Manihot esculenta Crantz) is an important tropical tuber crop grown in India. It is of South American origin that reached Indian shores through Portuguese travelers. Even though only a few varieties were introduced in the beginning, much variability developed by virtue of flowering and natural hybridisation. This variability, based on morphological and biometrical characters, has been occasionally studied. This paper is an attempt to assess this variability in a typical cassava growing area based on molecular markers and to analyse the factors promoting variability. SSR (Simple Sequence Repeat) markers are found to be ideal for analysing molecular variability in plant populations. Thirty six SSR markers developed at CIAT, Cali, Columbia and available in the public domain were chosen for the study. Thirty eight varieties of cassava were collected from a typical cassava-growing region, where high variability was noticed in tuber yield, starch content and cooking quality. Cassava yield in this area is comparatively high. DNA was extracted following standard protocols and was amplified using 36 SSR primers. Each primer produced one or two bands. The similarity between different varieties was quantified using the software package NTSYS-pc (Numerical Taxonomy Multivariate Analysis System). The similarity between varieties varied from 44 to 90%. A similarity matrix was used to construct a dendrogram using the Unweighted Pair Group Method with Arithmetic Means (UPGMA), to study the grouping pattern. The set of 38 varieties was grouped into five clusters. This information will be useful in planning hybridisation between distantly related varieties so that wide variation can be realized in the hybrid population. The wider the variability, the better will be the chance of selection of superior varieties.
Ajay Kumar Mishra, Kamal Sharma, Raj Shekhar Misra (India) Genetic Relatedness of Colocasia esculenta as Revealed by RAPDs (pp 97-101)
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Original Research Paper: Ten taro (Colocasia esculenta (L.) Schott) accessions collected from different parts of India were subjected to RAPD (Random Amplified Polymorphic DNA) analysis using eight random primers to assess the genetic diversity prevalent in them. Band sizes obtained ranged from 0.4 to 2 kb and the number of scorable bands per primer ranged from 1 to 13 with an average of 9.75 bands per primer. One quarter of the primers analyzed showed 100% polymorphism. The bands produced by the primers were distinct and reproducible. High genetic diversity was revealed by similarity coefficient values that ranged from 0.62 to 0.98. No two accessions analyzed in the present study showed a similarity coefficient value of one thereby indicating their distinctness and presence of high genetic diversity in Indian taro. A dendrogram obtained from UPGMA analysis grouped 10 accessions in two clusters. Clustering did not show any strict relationship with geographical distribution, morphotype classification and genotypic diversity. Forty-three loci or 84.31% were polymorphic. The presence of new recombination events by random and natural processes of mutation may have explained the high genetic diversity.
Santha V. Pillai, S. Sree Lekha (India) Molecular Variability in 45 Indian Taro Cultivars (pp 102-106)
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Original Research Paper: Taro(Colocasia esculenta L. Schott),belonging to the family Araceae, is a popular tuber crop grown in India. Taro shows high variability in morphological characters with plants being mostly of green or purple type with a range of shades in between. To assess the genetic variability and diversity available in the germplasm available at CTCRI Trivandrum, 45 taro accessions which showed distinct morphology were evaluated for genetic diversity using 11 Random Amplified Polymorphic DNA (RAPD) primers. Only three primers showed bands and they were used to analyse 45 taro accessions. These three primers are considered highly informative because they amplified one or more polymorphic bands that distinguished between accessions. The accessions studied showed high variability with regard to number of DNA bands. The similarity between different accessions was quantified using the software package NTSYS-pc (Numerical Taxonomy Multivariate Analysis System). Similarity between accessions varied from 60 to 100%. A dendrogram grouped the 45 accessions into 4 clusters and one outlier. Accessions collected from same geographical areas tended to cluster together. The data on genetic distance between accessions is useful for planning a hybridization programme while DNA fingerprinting can be used as an additional character to indicate the distinctiveness of a variety.
A. Manoj Kumar, Girija Ganeshan, Kalpana N. Reddy, Y. L. Ramachandra (India) Integrated Disease Management for the Control of Powdery Mildew (Leveillula taurica (Lev.) Arn.) in Bell Pepper (pp 107-112)
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Original Research Paper: Powdery mildew is a serious fungal disease in bell pepper leading to heavy yield losses both under greenhouse and field conditions. Initially the present study focused on the management of powdery mildew disease using several chemical and non-chemical treatments under field evaluation. The treatments included 13 chemical fungicides, 8 biological control agents, 13 plant extracts (botanicals) and the study was conducted in two experimental seasons during 2004-2005 in bell pepper varieties ‘California Wonder’ and ‘Indra’. Dinocap (1 ml l-1) among chemical fungicides, Ampelomyces quisqualis (20 g l-1) among biological control agents and neem oil (20 ml l-1) among botanicals recorded as the best components by recording a minimum per cent of disease index and the maximum yield compared to untreated controls. The same trend was observed in both seasons. In a second set of experiments, the most effective components were integrated to further minimize the use of fungicides thus an Integrated Disease Management (IDM) package was developed and tested in the field. By adopting this IDM the yield of ‘California Wonder’ and ‘Indra’ bell pepper showed an increase of 342. 8 and 122.3%, respectively; the corresponding values for the control were 93.6 and 93.2%, respectively. This new IDM package made possible to reduce dinocap spray to only one treatment. Hence, the developed technology appears very promising mainly because is economically feasible, increases the yield and is environmentally safe as it reduces the cost and increases the returns. |
