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Genetic Improvement of Timber Yield and Wood Quality in Eucalyptus Grandis (Hill) Maiden
Item type: Journal Article • Journal: South African Forestry Journal • Authors: G. van Wyk --- Division of Forest Science and Technology,Results of a partial diallel progeny test of Eucalyptus grandis assessed at ages 5, 36, 60 and 105 months are presented. Large genetic variations among full-sib families were found for all traits studied, e.g. the mean tree volume per family... -
An evaluation of two collections of South African maize (Zea mays L.) germ plasm: 1. The genetic basis of the synchronization of pollen shedding and silk emergence
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: B. de Jager --- Department of Genetics, C.Z. Roux --- Department of Genetics, H.C. Kühn --- ,Pollen shed-silking synchronization for a cultivar was measured by the interval between the dates on which 50% of the plants exhibited anthers and the dates on which 50% of the primary ears exhibited extruded silks. Under drought stress silking may... -
An evaluation of two collections of South African maize (Zea mays L.) germ plasm: 2. The genetic basis of dry-down rate
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: B. de Jager --- Department of Genetics, C.Z. Roux --- Department of Genetics, H.C. Kühn --- ,Dry-down rate is the loss of moisture from maize kernels over time. This study was undertaken to determine whether collections of early and late flowering South African germ plasm have the same genetic properties with reference to dry-down rate as... -
Phenotypic diversity for morphological and agronomic traits in traditional Ethiopian highland maize accessions
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: T. Beyene --- Department of Plant Sciences, A.M. Botha --- Department of Genetics, South Africa A.A. Myburg --- Department of Genetics, South AfricaFarmers in the highlands of Ethiopia have developed locally adapted maize varieties for more than 300 years. In order to assess the phenotypic diversity among traditional Ethiopian highland maize accessions, a total of 180 accessions were evaluated for agro-morphological traits... -
Optimum replications and crop-years for sugarcane genotype trials at Dwangwa Sugar Estate in Malawi
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: MM Zhou --- , South Africa A Chihana --- , Malawi RC Parfitt --- , South AfricaThe ability to detect significant differences among genotypes in trials depends on the variance associated with the means. Dwangwa Sugar Estate, Malawi, imports genotypes from the South African Sugarcane Research Institute (SASRI) to test for possible commercial release. The objective... -
Family selection gains for quality traits among South African sugarcane breeding populations
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: MM Zhou --- South African Sugarcane Research Institute, South Africa ML Lichakane --- South African Sugarcane Research Institute, South AfricaIn sugarcane breeding, family selection has been shown to produce larger gains than individual plant selection. During family selection, whole families of seedlings are selected or rejected based on data derived from replicated family plots. The objective of this study... -
An investigation into the occurrence and nature of genotype by environment interaction in Pinus patula
Item type: Journal Article • Journal: The Southern African Forestry Journal • Authors: C.L. Snedden --- , South Africa S.D. Verryn --- , South AfricaThis study was conducted as part of a joint venture between the tree improvement teams of Safcol and the CSIR to develop a breeding, production and conservation strategy for Pinus patula. -
Predicted and realized genetic gain in Eucalyptus grandis breeding seedling orchard in Zimbabwe
Item type: Journal Article • Journal: The Southern African Forestry Journal • Authors: W.J. GapareResults are presented of a fourth generation breeding seedling orchard of Eucalyptus grandis Hill Maiden of 30 half-sib families. Measurements at one and half and five years were available. Analysis of one and half year data showed no significant differences... -
Susceptibility of Corymbia species and hybrids to arthropod herbivory inAustralian subtropical hardwood plantations
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: HF Nahrung --- Agri-Science Queensland, Australia R Waugh --- Agri-Science Queensland, Australia DJ Lee --- Agri-Science Queensland, Australia SA Lawson --- Agri-Science Queensland, AustraliaCorymbia hybrids are becoming significant plantation varieties in subtropical and tropical Australian plantation forestry. Although primarily developed for disease resistance and amenability to clonal propagation, they have also proven to have good growth rates and site plasticity. Here we examined... -
Growth potential and genetic parameters of four Mesoamerican pines planted in the Southern Hemisphere
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: GR Hodge --- Department of Forestry and Natural Resources, USA WS Dvorak --- Department of Forestry and Natural Resources, USASummary results are reported from a total of 319 provenance/progeny tests of Pinus tecunumanii, P. maximinoi, P. patula and P. greggii that were established on sites in Brazil, Colombia and South Africa. Tests were measured for the growth traits height,... -
Genetic characterisation of a Eucalyptus nitens base breeding population in South Africa
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Tammy-L Swain --- Institute for Commercial Forestry Research, South Africa SteveD Verryn --- Forestry and Agricultural Biotechnology Institute, South Africa MarkD Laing --- School of Agricultural Earth and Environmental Sciences, South AfricaThe measurement and statistical analysis of data from eight Eucalyptus nitens trials, established in the summer rainfall forestry region of South Africa during the 1980s and 1990s, have enabled the characterisation of the Institute for Commercial Forestry Research's breeding population... -
Heritability of shoot die-back and root biomass in sixteen Pterocarpus angolensis (Fabaceae) half-sib families from Malawi, Namibia and Zambia
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: JP Mwitwa CRY Munthali G van WykThe experiment was conducted to ascertain narrow-sense heritability (h 2) and the family-within-provenance variation in shoot die-back, taproot length and root biomass of half-sib Pterocarpus angolensis families from Malawi, Namibia and Zambia. Provenances differed significantly in shoot die-back for both... -
Genetic control of wood density and bark thickness, and their correlations with diameter, in pure and hybrid populations of Eucalyptus grandis and E. urophylla in South Africa
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: ECL Retief TK StangerTree diameter under and over bark at breast height (dbh), wood density and bark thickness were assessed on samples from control-pollinated families of Eucalyptus grandis, E. urophylla, E. grandis × E. urophylla and E. urophylla × E. grandis. The material... -
Genetic parameters of pure and hybrid populations of Eucalyptus grandis and E. urophylla and implications for hybrid breeding strategy
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: ECL Retief TK StangerIn order to review Sappi Forests' breeding strategy for E. urophylla × E. grandis hybrids, information is required regarding the genetic control of certain traits and the correlations between them. A hybrid seedling progeny trial was planted, comprising material generated... -
Effect of temperature on cone bursting, seed extraction and germination in five provenances of Pinus roxburghii from Garhwal Himalaya in India
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: SK Ghildiyal CM Sharma S GairolaPinus roxburghii (chir pine or long-needle pine) is considered to be a fire-hardy species. In this study the effect of a wide range of elevated temperatures (from 40 °C to 150 °C) on cone bursting and subsequent seed germination was... -
Comparison of the tolerance of Pinus patula seedlings and established trees to infection by Fusarium circinatum
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: R Glen Mitchell --- York Timbers, South Africa Michael J Wingfield --- Forestry and Agricultural Biotechnology Institute, South Africa Emma T Steenkamp --- Forestry and Agricultural Biotechnology Institute, South Africa Jolanda Roux --- Forestry and Agricultural Biotechnology Institute, South Africa Steven Verryn --- Creation Breeding Innovations cc, South Africa Teresa A Coutinho --- Forestry and Agricultural Biotechnology Institute, South AfricaSince the first appearance of Fusarium circinatum in South Africa in 1990, foresters have been challenged with poor field survival of Pinus patula seedlings at establishment. One of the best long-term solutions is to improve the genetic tolerance of P... -
Genetic parameters for Fusarium circinatum tolerance within openpollinated families of Pinus patula tested at screening facilities in South Africa and the USA
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Andre Nel --- Sappi Forest Research, South Africa Gary R Hodge --- Department of Forestry and Natural Resources, USA Kgosi E Mongwaketsi --- Sappi Forest Research, South Africa Arnulf Kanzler --- Sappi Forest Research, South AfricaThe pine pitch canker fungus, Fusarium circinatum, has caused large-scale mortality of Pinus patula Schiede & Deppe ex Schltdl. & Cham. crops in South African nurseries. This disease is now managed with strict hygiene practices and mortality in commercial nurseries... -
Genetic variability in cowpea (Vigna unguiculata (L.) Walp.) genotypes
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Abe S Gerrano --- Agricultural Research Council–Roodeplaat Vegetable and Ornamental Plant Institute, South Africa Patrick O Adebola --- Agricultural Research Council–Roodeplaat Vegetable and Ornamental Plant Institute, South Africa Willem S Jansen van Rensburg --- Agricultural Research Council–Roodeplaat Vegetable and Ornamental Plant Institute, South Africa Sunette M Laurie --- Agricultural Research Council–Roodeplaat Vegetable and Ornamental Plant Institute, South AfricaInformation on genetic variability among the existing cowpea genotypes will increase the efficiency of the cowpea improvement. Field experiments were conducted at the Agricultural Research Council–Roodeplaat Vegetable and Ornamental Plant Institute in South Africa, in 2011 and 2012, to estimate... -
Genotypic variation and correlations between yield system traits and yield components in African landraces of bambara groundnut
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Olusanya C Alake --- Department of Plant Breeding and Seed Technology, Nigeria Moninuola A Ayo-Vaughan --- Department of Plant Breeding and Seed Technology, NigeriaGenetic information on a variety of traits contributing to grain yield is required to improve many crops. However, this information is lacking in bambara groundnut (Vigna subterranea (L.) Verdc.). To this end, 24 African bambara groundnut landraces were investigated for... -
Broad- and narrow-sense heritabilities in a South African cloned open-pollinated Eucalyptus grandis breeding population
Item type: Journal Article • Journal: Southern Hemisphere Forestry Journal • Authors: CL Snedden CZ Roux SD VerrynGenetic variances and heritabilities of a 66-month old cloned Eucalyptus grandis breeding population of families, derived from open-pollinated selections, were estimated. The genetic variance for the growth traits was largely additive genetic variance, whereas the proportion of non-additive genetic variance... -
Half-sib family variation in shoot and root traits of seedlings of Pterocarpus angolensis (family: Fabaceae; syn. Papilionaceae)
Item type: Journal Article • Journal: Southern Hemisphere Forestry Journal • Authors: JP Mwitwa CRY Munthali G van WykPhenotypic and genetic variation in shoot and root traits occurs between half-sib families from Malawi. Heritability was high for shoot height and root collar diameter (h 2 ≤ 0.90) while that for shoot and root traits was low to moderate... -
Assessment of three-year DBH and height data and genetic gain prediction for five Acacia mearnsii (black wattle) subpopulations in South Africa using REML/BLUP
Item type: Journal Article • Journal: Southern Hemisphere Forestry Journal • Authors: SL Beck J de Guisti AK Louw MDV ResendeRecent research has shown Acacia mearnsii (black wattle) to be a source of high-quality pulp. This led to a change in the emphasis in the breeding programme at the Institute for Commercial Forestry Research, from improving bark yield and quality,... -
Genetic variation in survival, growth, and stem form of Pinus leiophylla in Brazil and South Africa and provenance resistance to pitch canker
Item type: Journal Article • Journal: Southern Hemisphere Forestry Journal • Authors: WS Dvorak GR Hodge JE KietzkaPinus leiophylla is a relatively common pine that occurs in the mountains of western and central Mexico. Between 1987 and 1990, Camcore, North Carolina State University, sampled 11 populations and 309 mother trees of the species to determine patterns of... -
Genetic parameters and genotype by environment interaction of Eucalyptus grandis populations used in intraspecific hybrid production in South Africa
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Gert J van den Berg --- Mondi Forests (Pty) Ltd, South Africa Steven D Verryn --- , South Africa Paxie W Chirwa --- Faculty of Natural and Agricultural Sciences, South Africa Francois van Deventer --- Mondi Forests (Pty) Ltd, South AfricaIn South Africa, Eucalyptus grandis is an important species due to its fast growth and general suitability of its timber for a range of products. However, E. grandis is susceptible to fungal diseases such as Crysoporthe austroafricana and Coniothyrium sp... -
Trends in broad-sense heritability and predicted selection gains for the coastal short cycle breeding sugarcane programmes in South Africa
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Sphamandla Sengwayo --- South African Sugarcane Research Institute, South Africa Marvellous Zhou --- South African Sugarcane Research Institute, South Africa Maryke Labuschagne --- Department of Plant Sciences, South AfricaCoastal short cycle breeding programmes develop early maturing sugarcane cultivars adapted to harvesting at 12 months under rainfed conditions. Genotypes progressed to the advanced cultivar stage from these programmes are merged and evaluated concurrently in multi-environment trials across the region... -
Analysis of phenotypic variability for yield and quality traits within a collection of cassava (Manihot esculenta) genotypes
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Athanase Nduwumuremyi --- African Centre for Crop Improvement, South Africa Rob Melis --- African Centre for Crop Improvement, South Africa Paul Shanahan --- African Centre for Crop Improvement, South Africa Asiimwe Theodore --- Rwanda Agriculture Board, RwandaGenetic diversity is essential for crop improvement and knowledge of the genetic variability within a breeding population facilitates its future exploitation. This study examined the phenotypic and genetic variability for specific cassava key traits in a collection of 30 genotypes... -
Comparing family with individual genotype breeding parameters for cane yield in sugarcane populations
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Ntombokulunga W Mbuma --- South African Sugarcane Research Institute, South Africa Marvellous M Zhou --- South African Sugarcane Research Institute, South Africa Rouxlene van der Merwe --- Department of Plant Sciences, South AfricaFamily selection is the positive advancement of all progenies from a cross and is widely practiced in breeding for sugarcane and other crops. The objective of this study was to compare family with individual genotype selection (IGS) for cane yield... -
Variance components and heritability of yield and yield-related traits in tepary bean (Phaseolus acutifolius)
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Zinhle B Mhlaba --- African Centre for Crop Improvement, South Africa Hussein A Shimelis --- African Centre for Crop Improvement, South Africa Beyene Amelework --- African Centre for Crop Improvement, South Africa Albert T Modi --- School of Agricultural, Earth and Environmental Sciences, Discipline of Crop Science, South Africa Jacob Mashilo --- African Centre for Crop Improvement, South AfricaThe extent of variance and heritability of traits influence the response to selection in crop breeding programs. The objective of this study was to determine variance components and heritability in tepary bean (Phaseolus acutifolius A.Gray) populations to identify promising genotypes... -
Optimising the number of test sites, crop-years and replications to maximize post-release testing efficiencies
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Sbongeleni Warren Duma --- School of Agricultural, Earth and Environmental Sciences, South Africa Hussein Shimelis --- School of Agricultural, Earth and Environmental Sciences, South Africa Sanesh Ramburan --- School of Agricultural, Earth and Environmental Sciences, South Africa Admire Isaac Tichafa Shayanowako --- School of Agricultural, Earth and Environmental Sciences, South AfricaThe South African sugar industry develops commercial sugarcane cultivars across multiple testing sites, crop-years and replications. The extent of such parameters has not been well quantified for optimum breeding and resource allocation. The objective of this study was to identify... -
Genetic control of diameter and bark percentage in spotted gum (Corymbia spp.): can we breed eucalypts with more wood and less bark?
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: João Gabriel Zanon Paludeto --- , Brazil David Bush --- , Australia Regiane Abjaud Estopa --- , Brazil Evandro Vagner Tambarussi --- , BrazilThis study aimed to estimate the genetic parameters of diameter at breast height over bark (DBHOB), bark percentage (Bark%) and the correlation between DBHOB and Bark% for Corymbia spp. Three independent trials were evaluated during this study: C. variegata (CV)... -
Assessment of genetic diversity in sorghum germplasm using agro-morphological traits
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Thulo Sejake --- , South Africa Nemera Shargie --- , South Africa Riann Christian --- , South Africa Toi Tsilo --- , South AfricaSorghum is one of the most important cereal crops grown in arid/semi-arid regions of the world. Despite its importance, sorghum production and productivity are constrained by the use of low yielding cultivars, which are susceptible to biotic and abiotic stresses... -
Genetic analysis of Panicum coloratum var. makarikariense caryopsis retention
Item type: Journal Article • Journal: African Journal of Range & Forage Science • Authors: María FM Lirusso --- Instituto de Investigaciones en Ciencias Agrarias de Rosario, Universidad Nacional de Rosario, Argentina Florencia I Pozzi --- Instituto de Investigaciones en Ciencias Agrarias de Rosario, Universidad Nacional de Rosario, Argentina Guillermo R Pratta --- Instituto de Investigaciones en Ciencias Agrarias de Rosario, Universidad Nacional de Rosario, Argentina Silvina A Felitti --- Instituto de Investigaciones en Ciencias Agrarias de Rosario, Universidad Nacional de Rosario, ArgentinaPanicum coloratum is a species of C4 type grass native to South Africa. In Argentina, it is valued for its production of good quality forage in environments where resources are limiting, although it is infrequently cultivated in livestock systems. The... -
Estimation of genetic parameters for growth in a population of Eucalyptus grandis × Eucalyptus nitens hybrids in KwaZulu-Natal and Mpumalanga
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: W Brink --- Sappi Shaw Research Centre, South Africa G van den Berg --- Sappi Shaw Research Centre, South Africa A Nel --- Sappi Shaw Research Centre, South Africa B du Toit --- University of Stellenbosch, South AfricaHybridising Eucalyptus grandis with Eucalyptus nitens produces progeny intended to combine the favourable traits of both parents. E. grandis exhibits good growth, stem form, wood properties and rooting ability for vegetative propagation. E. nitens displays superior cold tolerance, including superior... -
Genetic control of Fusarium circinatum tolerance in Pinus patula × P. tecunumanii hybrid families
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Lebogang Mphahlele --- , South Africa André Nel --- , South AfricaThe pine pitch canker fungus, Fusarium circinatum, has caused large-scale mortality of Pinus patula crops in South African nurseries and high in-field post-planting mortality. Tree breeders have identified selection and breeding of tolerant material as the likely long-term solution to... -
Genetic, breeding and environmental parameters for yellow sugarcane aphid (Sipha flava) damage in advanced South African sugarcane breeding populations
Item type: Journal Article • Journal: South African Journal of Plant and Soil • Authors: Marvellous Zhou --- South African Sugarcane Research Institute, South AfricaYellow sugarcane aphid (YSA), a native pest of temperate and subtropical regions in North America, has spread to many regions of the world including KwaZulu-Natal and Mpumalanga sugarcane growing regions of South Africa. Cultivar differences to YSA damage have been... -
Provenance variation, genetic parameters, and potential gains in Eucalyptus viminalis subsp. nobilis tested in two high altitude cool temperate sites in the summer rainfall region of South Africa
Item type: Journal Article • Journal: Southern Forests: a Journal of Forest Science • Authors: Christopher Komakech --- , South Africa Annabel Fossey --- , South AfricaOver the past 50 years, commercial forestry in South Africa has expanded into mid and high altitude summer rainfall regions, predominantly planting Eucalyptus nitens and Eucalyptus macarthurii. However, the suitability of these sites is increasingly threatened by projected climate changes...