Tea (Camellia Sinensis) Breeding in Nigeria: Past and Present Status (original) (raw)
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Identification of germplasm accessions for inclusion in the breeding programme is vital to widen the genetic base of the cultivated gene pool aiming at genetic enhancement and increased crop productivity. The present study was attempted to characterize 35 Sri Lankan tea germplasm based on yield related traits; 100g of harvest; 2 leaves and a bud, 3 leaves and a bud, dormant shoots (banji) with their fresh and dry weights. Principle component analysis (PCA) and clustering of first two principle components accounted for 90% of the total variation and delineated the 35 accessions into three clusters. The fresh and dry weights of active shoots (both 2 leaves and bud; 3 leaves and bud) and dormant shoots significantly contributed to the PCs loading. DUN 7 had the highest numbers of 2 leaves and bud followed by TC 9 and TRI 2043 whereas WT 26 had the lowest. Conversely, H1/58 had the highest numbers of dormant shoots followed by TRI 3013 and WT 26 and TRI 777 had the lowest. The significant variation of yield related traits have been identified and those parameters can be used for selecting parents for controlled hybridization, screen large progenies in progeny trials and even in selecting elite cultivars from old seedling tea fields (estate cultivar selections programmes).
International Journal of Forestry and Horticulture, 2017
Tea [Camellia sinensis (L) O. Kuntze], is one of the most popular and lowest cost beverages in the world, and consumed by a wide range of age groups in all levels of society with more than three billion cups daily worldwide (Hick, 2009). Majority of the tea producing countries are located in the continent of Asia where China, India, Sri Lanka are the major producers. African tea growing countries are located mostly around the tropical regions where Kenya, Malawi, Rwanda, Tanzania, Uganda are major producers. Apart from these regions, some quantities of tea are also being produced in South America (Argentina, Brazil and others), the Near East (Iran and Turkey) and the CIS (Russia and Georgia). Amongst tea producing countries, the principal producers are China, India, Sri Lanka, Kenya and Indonesia. In terms of area under tea plantation, on an average during the last two decade (1991-2010), China lead (45%) the world followed by India (21%), Sri Lanka (7%), Kenya (5%), Vietnam (3%) (Basu et al, 2012). The Tea Research Institute (TRI) is the only comprehensive institute dedicated to tea research at the national level in China. The institute holds the second largest tea preservation resource in the world and currently conserves 3,013 different tea germplasm resources, encompassing the most genetic diversity of any tea resource in the world. In total, researchers at TRI have contributed 225 scientific and technological advances to the field 106 of these achievements have been recognized with awards, including eight national and 39 ministerial prizes. The institute has bred eight nationally certified tea varieties, has been granted 45 patents, and has established one international standard, 25 national standards, and 51 industrial standards for tea production (Sean, 2013). The first tea planted in Africa was in 1850 in the Durban Botanical Garden on the eastern shore of South Africa near the port of Durban which was China type. In order to improve yield and quality of the crop in Southern Africa the Tea Research Foundation of Central Africa (TRFCA) was established in Malawi in 1933, initially as a tea research station under the department of agriculture before gaining autonomy in 1966. The TRFCA has an active plant breeding and selection program aimed at solving tea production problems such as drought, extreme temperatures, pests and diseases, low yield and low quality, under local Abstract: Tea [Camellia sinensis (L.) O. Kuntze] is one of the most popular and lowest cost beverages in the world, and consumed by a wide range of age groups in all levels of society with more than three billion cups daily worldwide. Tea breeding strategy such as source of gene pool, selection of elite mother bushes and assessment of made tea quality reviewed. Tea research achievement in breeding, eco-physiology, and biochemical; production of tea in China, India, Kenya, Sri Lanka and Vietnam was considered. The challenges like mini-manufacture, cost assessment, climate change, time consuming protocols, pest and diseases; cost of assessment including constraints of Ethiopian tea industry was reviewed well. Future prospects of tea research main research emphases of tea genetics and breeding in the future, deepening the functional genome research to reveal special gene resources, enhancing the basic genetic research for breeding, conducting distant hybridization to enhance germplasm innovation, improving gene transformation technique to use exogenous genes, Perfecting molecular marker assisted technique to effectively conduct early-stage appraisal and similar procedures should be integrated in the future tea research in order to cope up with the currently existing environmental phenomena.
Variability analysis of some genotypes in Nigeria tea (Camellia sinensis) germplasm
World Journal of Advanced Research and Reviews, 2021
Thirty four tea clones were sourced from Cocoa Research Institute of Nigeria tea germplasm and raised through stem cuttings for 10 months in the nursery. The experiment was laid out in a randomized complete block design (RCBD) with 3 replications in 2016. Agronomic and yield data were collected and subjected to analysis of variance. Single linkage cluster analysis (SLCA), principal component analysis (PCA) and FATCLUS analysis were employed to analyse the data. ANOVA showed considerable significant variation p<0.05 among the 34 tea genotypes. The PCA showed that Plant Height (PH) 0.39, Number of Leaves (NL) 0.38, Number of Branches (NB) 0.37, Harvestable Points (HP) 0.31, Stem Diameter 0.39 and Leaf Breadth 0.30 accounted for most of the variations observed. Axes 1, 2 and 3 of the PCA accounted for 37.23%, 15.48% and 10.75% variability respectively with cumulative value of 63.47%. The genotypes were clustered into 7 groups by FASTCLUS Analysis. The dendrogram showed that the firs...
Genetic improvement of tea for both health and economic benefit requires proper genetic characterization of sequence variation present in tea accession especially those conserved in the ex-situ genebanks. Here, we studied the genetic variation and population structure of 376 tea germplasm at Rwebitaba Tea Research Centre (RTRC), a tea research station with the largest collections of tea germplasm in East Africa. The study was conducted using 8480 (22.7%) diversity array technology (DArT) SNP markers. These markers had a high call rate of 77% with mean polymorphic information content (P.I.C) of 0.12 and minor allelic frequency of 0.08. The expected heterozygosity (He) varied from 0.05 to 0.15 while the observed heterozygosity (Ho) varied from 0.01 to 0.26. The overall inbreeding coefficient (FIS) was 0.45, with some populations showing a high level of outcrossing (F IS = − 0.035). Analysis of molecular variance revealed a high within-population variance (88.9%) showing weak genetic differentiation between populations (PhiPT = 0.111). Structure analysis showed the presence of eight clusters, with all sub-populations highly admixed except for a few tea clones such as Ch-06 and Ch-07. Phylogenetic analysis confirmed the clustering, showing interrelatedness between different tea genotypes, which will facilitate the selection of parents for increased genetic gain and breeding efficiency in tea breeding. In general, the genetic diversity of tea genotypes is relatively low, with high variation within the existing tea populations. These results showed that the existing variation can be exploited for the development of unique tea genotypes in Uganda.
African Journal of Agricultural Research
Tea has long been a well-known crop for its economic value and widening the genetic variability of tea family is often necessitated. Hybridization programs at intraspecific level have been greatly fascinated as potential and useful methods in tea plant breeding to widening the genetic diversity. This comparative study was intended to explore a new avenue to develop the tea plant breeding programs through evaluating remote intraspecific cross-compatibility between Camellia sinensis var. sinensis (L.) O. Kuntze and C. sinensis var. assamica (Masters). Remote intraspecific cross-compatibility was assessed by comparing and contrasting the in-vivo pollen germination and pollen tube growth using fluorescence microscopy and the subsequent fruit set following controlled self-and cross-pollinations. In-vivo pollen germination and pollen tube growth was examined at 1 day, 3 days, and 14 days after pollination treatments, but disparity was not observed in pollen germination and pollen tube growth between self-and cross-pollinations. Early fruit set was evaluated at 3 months and 6 months after pollination. Fruit set was observed in cross-pollination except self-pollination. A late-acting selfincompatibility system or post-zygotic barriers and close intraspecific cross-compatibility were confirmed within C. sinensis var. sinensis (L.) O. Kuntze. Potential remote intraspecific crosscompatibility was recorded from cultivars crossed between China type and Assam type tea. The present findings bestow the significant contribution to develop the future tea breeding programs.
Sri Lanka Journal of Food and Agriculture, 2019
Tea germplasm accessions are the most valuable material for tea breeding. However its utilization in the past was limited due to lack of available information. Recently generated information on genetic structure and metabolite profiles of the germplasm were used in selecting parents for hybridization programmes from 2012 to 2016. The main focus of the programme was to make crosses between three taxa of tea viz. Camellia. sinensis var. assamica (Assam type), C. sinensis var. sinensis (China type) and C. sinensis spp. lasiocalyx (Cambod type). Pollinated buds were closelymonitored and the number of crosses, number of fruits, number of seeds and reproductive parameters were recorded. A total of 3978 crosses (2405 direct crosses and 1573 reciprocal crosses) were made and 974 seeds were obtained from 595 fruits. Percentages of fruit set and seed set varied significantly among different families. Irrespective of the intersubspecies groups, the percentage of seed germination was above 50% and was not significantly-different. Cross compatibility between taxa in terms of percentage of fruit set ranged from 4.6% to 25.6% and varied significantly. Among the inter-subspecies crosses the Assam varieties were found to be the best as female parent. The generated information would be useful for selection of parents and tea improvement programmes in the future.
Floriculture, Ornamental and Plant Biotechnology: Advances and Topical Issues Vol. I, 2006
Tea is the most popular non-alcoholic soft and healthy beverage across the globe and is an increasingly popular ornamental plant, easily found as a garden hedge in SE Asia. It has socioeconomic and cultural importance and potential for some Asian and African countries, such as China, India, Japan, Sri Lanka and Kenya. Tea genetic resources are fundamental materials for production utilization, cultivar innovation and biotechnology research. In this chapter, the achievements and progress of tea genetic resource research in China in the last two decades are systematically reviewed from the following viewpoints: investigation and collection, conservation and cataloguing, appraisal and evaluation, as well as utilization. The authors also discuss the prospects of tea genetic resource research in China.
Nucleation and Atmospheric Aerosols, 2019
Tea is a cross-pollinated and self-incompatible plant. Consequently, it has a very high genetic diversity. This research was aimed to estimate the variability of morphological and molecular characteristics of five accessions which exploited to develop high quality and quantity yield at PT. Pagilaran and compare the efficiency and accuracy of the use of morphological and molecular markers in tea characterization. The accessions consist of three C. assamica tea accessions (TRI 2025, Cinyiruan 143, and Kiara 8), and two C. sinensis tea accessions (Tambi and Tambi Jingga). Morphological observation includes leaf length, leaf width, stalk length, total pekoe, fresh leaf weight, stalk fresh weight, fresh pekoe weight, dry leaf weight, stalk dry weight, and pekoe dry weight, while the molecular observation was performed using SSR markers. Morphological data were analysed using 5 % ANOVA with Tukey-Kramer test and PCA Biplot using SAS 9.4 and R software, whereas the molecular binary data were analysed using the GenAlEx 6 software to estimate variance components, the percentage of polymorphism, and the total number of alleles and specific loci. The dendrogram was created using the Cluster procedure in SAS 9.4. The results showed that molecular characterization provides SSRs markers are more effective for putative genetic markers characterization, and every accession has its own morphological and SSR putative markers.
Pakistan Journal of Agricultural Research, 2021
T ea (Camellia sinensis L.) is one of the important healthy beverages used globally and being cultivated in more than thirty countries in different tropical and subtropical zones of the World (Adnan et al., 2013) having above eighty two genetically distinct species (Sultana et al., 2008). Tea cultivation contributes manifolds in improving the economy and job opportunities status in various Asian and African Abstract | The present study was conducted at the tea nursery farm of PARC-National Tea and High Value Crops Research Institute, Shinkiari, Mansehra, Pakistan during the years 2014-16 to assess genetic variability, heritability and genetic advance as percent of mean for various growth attributing traits of fifteen early flushing tea (Camellia sinensis L) clones. The experiment was laid out in randomized complete block design (RCBD) with three replication and 100 plants per replication. Data were recorded on plant height (PH), number of branches per plant (NBP), number of leaves per plant (NLP), stem diameter (SD), main root length (MRL), root diameter (RD), number of lateral roots per plant (NLRP), dry shoot weight (DRW) and dry root weight (DRW). The highest plant height (78.66 cm) was produced by clone BP 2-2, followed by Clones BP 1-4, BP 1-3, BP 3-1 and BP 2-5 with plant height of 70.46, 67.60, 67.20 and 66.36 cm respectively. Clone BP 2-2 also produced highest number of leaves per plant (34.66), stem diameter (6.53 mm), root length (35.10 cm), root diameter (6.55 mm), number of lateral roots per plant (6.35), Dry shoot weight (17.56 g) and dry root weight (11.57 g). Number of branches per plant in the early flushing tea clones ranged from 1.33 (BP 2-4) to 6.00 (BP 6-1). The phenotypic coefficient of variation (PCV) was higher than genotypic coefficient of variation (GCV), but the difference between PCV and GCV was minimal for most of the traits revealing little influence of the environment in the expression of these traits.
2016
Africa is one of the key centers of global tea production. Understanding the genetic diversity and relationships of cultivars of African tea is important for future targeted breeding efforts for new crop cultivars, specialty tea processing, and to guide germplasm conservation efforts. Despite the economic importance of tea in Africa, no research work has been done so far on its genetic diversity at a continental scale. Twenty-three nSSRs and three plastid DNA regions were used to investigate the genetic diversity, relationships, and breeding patterns of tea accessions collected from eight countries of Africa. A total of 280 African tea accessions generated 297 alleles with a mean of 12.91 alleles per locus and a genetic diversity (H S) estimate of 0.652. A STRUCTURE analysis suggested two main genetic groups of African tea accessions which corresponded well with the two tea types Camellia sinensis var. sinensis and C. sinensis var. assamica, respectively, as well as an admixed "mosaic" group whose individuals were defined as hybrids of F2 and BC generation with a high proportion of C. sinensis var. assamica being maternal parents. Accessions known to be C. sinensis var. assamica further separated into two groups representing the two major tea breeding centers corresponding to southern Africa (Tea Research Foundation of Central Africa, TRFCA), and East Africa (Tea Research Foundation of Kenya, TRFK). Tea accessions were shared among countries. African tea has relatively lower genetic diversity. C. sinensis var. assamica is the main tea type under cultivation and contributes more in tea breeding improvements in Africa. International germplasm exchange and movement among countries within Africa was confirmed. The clustering into two main breeding centers, TRFCA, and TRFK, suggested that some traits of C. sinensis var. assamica and their associated genes possibly underwent selection Wambulwa et al. Genetic Architecture of African Tea during geographic differentiation or local breeding preferences. This study represents the first step toward effective utilization of differently inherited molecular markers for exploring the breeding status of African tea. The findings here will be important for planning the exploration, utilization, and conservation of tea germplasm for future breeding efforts in Africa.