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Anatomy of the Root of Pigeonpea (Cajanus cajan)  [PDF]
Shahanara Begum,A.K.M. Azad-ud-doula Prodhan
Pakistan Journal of Biological Sciences , 2003,
Abstract: Anatomical investigation has been made on the root of pigeonpea (Cajanus cajan (L.) Millsp.) at different stages of growth following the standard paraffin method of microtechnique. The root of pigeonpea is tetrarch with 4 strands of xylem and 4 strands of phloem. One strand of xylem alternates with one strand of phloem. The four opposite strands of primary xylem meet at the centre. Subsequently metaxylem forms near the centre on either side of the xylem strand. Ultimately the centre is filled up with big metaxylem vessels. The epidermis is single layered with root hairs and glandular trichomes. There are 8-13 layers of cortical cells in the root of pigeonpea. The cambium appears in the basal part of the root of 3-4 days old plant. Gradually it extends towards the root apex. The activity of cambium is similar to that of woody dicotyledonous herb. In the mature root, most of the vessels in the secondary xylem are solitary while the others are paired or multiple. The fibre cells in the phloem are arranged in groups. The fibre groups are radially arranged in such a way that the structure seems to be a pyramid. The epidermis is ruptured here and there, and the epidermal cells are disorganized due to the stress of secondary growth. Periderm is formed in the root one after another as the root increases in diameter.
Modifications on leaf anatomy of Coffea arabica caused by shade of pigeonpea (Cajanus cajan)
Morais, Heverly;Medri, Moacyr Eurípedes;Marur, Celso Jamil;Caramori, Paulo Henrique;Ribeiro, Ana Maria de Arruda;Gomes, José Carlos;
Brazilian Archives of Biology and Technology , 2004, DOI: 10.1590/S1516-89132004000600005
Abstract: modifications on leaf anatomy in coffea arabica shaded with pigeonpea (cajanus cajan), compared to cultivation under full sun, were assessed. the leaves fully exposed to sunlight presented thicker cuticles and cellular walls, narrower epidermis cells, palisade parenchyma with longer cells, thicker lacunar parenchyma, fewer intercellular spaces and a larger stomata number. leaves under dense shade presented a narrower cuticle and cellular wall; a mesophyll with smaller volume, but with larger intercellular spaces; and epidermis with thicker cells and a smaller stomata amount, surrounded by subsidiary cells of smaller dimensions. plants grown under full sunlight presented higher values of net photosynthesis. the results evidenced that the species c. arabica has a wide range of phenotypic adaptation to changes in the radiation intensity.
Development of genic-SSR markers by deep transcriptome sequencing in pigeonpea [Cajanus cajan (L.) Millspaugh]
Sutapa Dutta, Giriraj Kumawat, Bikram P Singh, Deepak K Gupta, Sangeeta Singh, Vivek Dogra, Kishor Gaikwad, Tilak R Sharma, Ranjeet S Raje, Tapas K Bandhopadhya, Subhojit Datta, Mahendra N Singh, Fakrudin Bashasab, Pawan Kulwal, KB Wanjari, Rajeev K Varshney, Douglas R Cook, Nagendra K Singh
BMC Plant Biology , 2011, DOI: 10.1186/1471-2229-11-17
Abstract: In this study, 43,324 transcriptome shotgun assembly unigene contigs were assembled from 1.696 million 454 GS-FLX sequence reads of separate pooled cDNA libraries prepared from leaf, root, stem and immature seed of two pigeonpea varieties, Asha and UPAS 120. A total of 3,771 genic-SSR loci, excluding homopolymeric and compound repeats, were identified; of which 2,877 PCR primer pairs were designed for marker development. Dinucleotide was the most common repeat motif with a frequency of 60.41%, followed by tri- (34.52%), hexa- (2.62%), tetra- (1.67%) and pentanucleotide (0.76%) repeat motifs. Primers were synthesized and tested for 772 of these loci with repeat lengths of ≥18 bp. Of these, 550 markers were validated for consistent amplification in eight diverse pigeonpea varieties; 71 were found to be polymorphic on agarose gel electrophoresis. Genetic diversity analysis was done on 22 pigeonpea varieties and eight wild species using 20 highly polymorphic genic-SSR markers. The number of alleles at these loci ranged from 4-10 and the polymorphism information content values ranged from 0.46 to 0.72. Neighbor-joining dendrogram showed distinct separation of the different groups of pigeonpea cultivars and wild species. Deep transcriptome sequencing of the two parental lines helped in silico identification of polymorphic genic-SSR loci to facilitate the rapid development of an intra-species reference genetic map, a subset of which was validated for expected allelic segregation in the reference mapping population.We developed 550 validated genic-SSR markers in pigeonpea using deep transcriptome sequencing. From these, 20 highly polymorphic markers were used to evaluate the genetic relationship among species of the genus Cajanus. A comprehensive set of genic-SSR markers was developed as an important genomic resource for diversity analysis and genetic mapping in pigeonpea.Pigeonpea [Cajanus cajan (L.) Millspaugh] is an important food legume predominantly cultivated in the t
New microsatellite markers for pigeonpea (cajanus cajan (L.) millsp.)
DA Odeny, Jayashree B, C Gebhardt, J Crouch
BMC Research Notes , 2009, DOI: 10.1186/1756-0500-2-35
Abstract: Primers were designed for 113 pigeonpea genomic SSRs, 73 of which amplified interpretable bands. Thirty-five of the primers revealed polymorphism among 24 pigeonpea breeding lines. The number of alleles detected ranged from 2 to 6 with a total of 110 alleles and an average of 3.1 alleles per locus. GT/CA and GAA class of repeats were the most abundant di-nucleotide and tri-nucleotide repeats respectively. Additionally, 220 soybean primers were tested in pigeonpea, 39 of which amplified interpretable bands.Despite the observed morphological diversity, there is little genetic diversity within cultivated pigeonpea as revealed by the developed microsatellites. Although some of the tested soybean microsatellites may be transferable to pigeonpea, lack of useful polymorphism may hinder their full use. A robust set of markers will still have to be developed for pigeonpea genome if molecular breeding is to be achieved.The increasing concern of the effect of global climate change and its likely impact on agriculture has stimulated scientists to search for crops that can withstand extreme environmental conditions. Among legumes, pigeonpea {Cajanus cajan (L.) Millspaugh} (2n = 22) has attracted attention as being both drought-tolerant [1] and highly nutritious [2]. Extensive morphological variation within the genus Cajanus as a whole and in cultivated species in particular has always led to the assumption that there exists abundant genetic diversity within the cultivated species. To the contrary, molecular studies have reported extremely low levels of polymorphism within the cultivated species compared to its wild relatives [3,4]. Such findings suggest that efforts towards the development of a linkage map of pigeonpea should focus on the use of an interspecific cross, and the development of a substantially high number of markers. We report the development of new 36 polymorphic simple sequence repeat (SSR) markers that will be an asset in characterising and understanding the nat
Gene effects, heterosis and inbreeding depression in Pigeonpea, Cajanus cajan L.
C.V.Sameer Kumar, Ch.Sreelakshmi and D.Shivani
Electronic Journal of Plant Breeding , 2012,
Abstract: The P1, P2, F1, F2, B1 and B2 of four pigeonpea, Cajanus cajan L. crosses were studied for eight metric traits. Individualscaling tests and joint scaling test indicated that an additive-dominance model was adequate in viz., PRG 100 x ICPL 87119,LRG 300 x ICP 8863 for number of primary branches per plant and LRG 300 x ICP 87119 for number of primary branches perplant and number of pods per plant. The results of the rest of the cases suggested the presence of additive, dominance andepistatic gene effects especially for the traits viz., seed yield and test weight.. Duplicate type of epistasis was prevalent in most ofthe cases. A substantial amount of heterobeltiosis over better parent (HBP) was revealed in all the four crosses for seed yield perplant and for most of its attributes. Inbreeding depression was also observed significant for days to 50% flowering, days tomaturity and number of clusters per plant in the cross PRG 100 x ICPL 87119 indicating the presence of dominance gene action.Suitable breeding strategies were suggested for the improvement of seed yield in pigeonpea.
Genetic Patterns of Domestication in Pigeonpea (Cajanus cajan (L.) Millsp.) and Wild Cajanus Relatives  [PDF]
Mulualem T. Kassa, R. Varma Penmetsa, Noelia Carrasquilla-Garcia, Birinchi K. Sarma, Subhojit Datta, Hari D. Upadhyaya, Rajeev K. Varshney, Eric J. B. von Wettberg, Douglas R. Cook
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0039563
Abstract: Pigeonpea (Cajanus cajan) is an annual or short-lived perennial food legume of acute regional importance, providing significant protein to the human diet in less developed regions of Asia and Africa. Due to its narrow genetic base, pigeonpea improvement is increasingly reliant on introgression of valuable traits from wild forms, a practice that would benefit from knowledge of its domestication history and relationships to wild species. Here we use 752 single nucleotide polymorphisms (SNPs) derived from 670 low copy orthologous genes to clarify the evolutionary history of pigeonpea (79 accessions) and its wild relatives (31 accessions). We identified three well-supported lineages that are geographically clustered and congruent with previous nuclear and plastid sequence-based phylogenies. Among all species analyzed Cajanus cajanifolius is the most probable progenitor of cultivated pigeonpea. Multiple lines of evidence suggest recent gene flow between cultivated and non-cultivated forms, as well as historical gene flow between diverged but sympatric species. Evidence supports that primary domestication occurred in India, with a second and more recent nested population bottleneck focused in tropical regions that is the likely consequence of pigeonpea breeding. We find abundant allelic variation and genetic diversity among the wild relatives, with the exception of wild species from Australia for which we report a third bottleneck unrelated to domestication within India. Domesticated C. cajan possess 75% less allelic diversity than the progenitor clade of wild Indian species, indicating a severe “domestication bottleneck” during pigeonpea domestication.
natomy of the Rachis of the Inflorescence of Pigeonpea (Cajanus cajan)  [PDF]
Shahanara Begum,Md. Azharul Islam,A.K.M. Azad-ud-doula Prodhan
International Journal of Botany , 2007,
Abstract: The anatomical investigation of the rachis has been made on the basis of flower removal. Two different types of rachis have been investigated. One type of rachis is normal (control) which develops naturally up to maturity and another type is deflowered (treated) where flowers and buds have been removed from the basal 3 nodes and then allows the rachis to develop naturally up to maturity. After removal of flowers and buds, pods are found to be set in 4-6 nodes of the same rachis. The internal structure of rachis is more or less similar to that of the stem. Epidermis bears multicellular hairs and glandular trichomes. The vascular tissue decreases gradually from base upward. The vascular tissue become highly developed in the deflowered rachis. The cambium is highly active on its adaxial side and produces a large amount of secondary xylem adaxially and well developed sieve tube elements abaxially. Some large vessels are formed in the abaxial region of the xylem. In the middle and upper parts of the deflowered rachis, the radial dimension of xylem is several times higher than the corresponding part of the normal rachis. The vascular tissue is poorly developed in the apical part of the normal rachis. The xylem is mainly composed of fibre cells with ray parenchyma which is uniseriate or multiseriate. Pericycle is discontinuous at the basal part and gradually it forms a more or less continuous ring towards the apical part around the vascular cylinder. Tanniniferous cells are more in the normal rachis compared to that of the deflowered rachis.
Identification and Validation of Expressed Sequence Tags from Pigeonpea (Cajanus cajan L.) Root  [PDF]
Ravi Ranjan Kumar,Shailesh Yadav,Shourabh Joshi,Prithviraj P. Bhandare,Vinod Kumar Patil,Pramod B. Kulkarni,Swati Sonkawade,G. R. Naik
International Journal of Plant Genomics , 2014, DOI: 10.1155/2014/651912
Abstract: Pigeonpea (Cajanus cajan (L) Millsp.) is an important food legume crop of rain fed agriculture in the arid and semiarid tropics of the world. It has deep and extensive root system which serves a number of important physiological and metabolic functions in plant development and growth. In order to identify genes associated with pigeonpea root, ESTs were generated from the root tissues of pigeonpea (GRG-295 genotype) by normalized cDNA library. A total of 105 high quality ESTs were generated by sequencing of 250 random clones which resulted in 72 unigenes comprising 25 contigs and 47 singlets. The ESTs were assigned to 9 functional categories on the basis of their putative function. In order to validate the possible expression of transcripts, four genes, namely, S-adenosylmethionine synthetase, phosphoglycerate kinase, serine carboxypeptidase, and methionine aminopeptidase, were further analyzed by reverse transcriptase PCR. The possible role of the identified transcripts and their functions associated with root will also be a valuable resource for the functional genomics study in legume crop. 1. Introduction Pigeonpea (Cajanus cajan L.) Millsp. ( ) is a major grain legume of the arid and semiarid regions of the world [1]. Though considered a minor crop, pigeonpea is of considerable importance in areas of South Asia (mainly on the Indian subcontinent), Africa, the Caribbean, and Latin America, where it is a prominent source of protein in the human diet, as well as wood for fuel and light duty structural applications such as thatch for roofing [2]. Pigeonpea has now moved from an “orphan legume crop” to one of the promising pluses where genomics-assisted breeding approaches for a sustainable crop improvement are routine by Pigeonpea Genome Initiative, an effort of various researchers [3]. The first pigeonpea EST dataset provides a transcriptomic resource for gene discovery and development of functional markers associated with biotic stress resistance [4]. Root is the major part of water and nutrition uptake in pigeonpea which has a deep and extensive root system that provides access to water stored deep in the soil profile when that in the surface layer is depleted; this source of water is particularly important for long duration crops. In order to identify the associated genes in pigeonpea root tissues, a normalized cDNA library was constructed from pigeonpea root and expression analysis of the identified genes was carried out by reverse transcriptase PCR (RT-PCR) technique. 2. Materials and Methods The pigeonpea genotype, namely, GRG-295 was selected to
Evaluation of the shoot regeneration response in tissue culture of pigeonpea (Cajanus cajan [L.] Millsp.) varieties adapted to eastern and southern Africa
S de Villiers, Q Emongor, R Njeri, E Gwata, D Hoisington, I Njagi, S Silim, K Sharma
African Journal of Biotechnology , 2008,
Abstract: Seven varieties of pigeonpea (Cajanus cajan [L.] Millsp.) of varying growth durations and adapted to a wide range of environments across eastern and southern Africa were evaluated for their shoot regeneration response in tissue culture. On a standardized shoot regeneration medium, the short duration varieties (ICPV 88091 and ICPV 86012) generally responded faster and better than the medium duration (ICEAP 00554 and ICEAP 00557) and long duration (ICEAP 00020, ICEAP 00040 and ICEAP 00053) varieties. However, all the tested varieties produced healthy rooted plants in vitro that could be transferred to the greenhouse where they exhibited normal growth, flowering and viable seed set. This study established the basis for genetic engineering of African pigeonpea varieties.
Inheritance of sterility mosaic disease resistance to Bangalore and Patancheru isolates in pigeonpea (Cajanus cajan (L.) Millsp.)
B.N. Gnanesh,, K.N. Ganapathy, B.C. Ajay, M. Byre Gowda
Electronic Journal of Plant Breeding , 2011,
Abstract: Sterility mosaic disease (SMD), is an important biotic constraint in pigeonpea (Cajanus cajan (L.) Millsp.) in Indiansubcontinent. It is caused by a virus and transmitted by eriophyid mites, Aceria cajani Channabasavanna. A comprehensive studyof variability in the sterility mosaic pathogen revealed the occurrence of five different isolates in India. Amongst them, threedistinct isolates have been characterised, viz., Bangalore, Patancheru and Coimbatore. Studies were conducted at Bangalore andPatancheru to determine the inheritance of resistance to Bangalore and Patancheru isolates of the SMD involving a resistant (ICP7035) and susceptible (TTB 7) genotypes. Observations in parents, F1 indicated dominance of susceptibility over resistance. Thedisease reaction of the individual F2 plant derived F3 families for Patancheru isolate was controlled by two genes with dominanceepistasis and for Bangalore isolate, absence of resistant plants indicate action of two or more genes in controlling resistance toSMD.
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