Libary Database

Author : Santchurn, D.
Title : Evaluation and selection of different types of sugarcane varieties for multi-purpose use from a population of inter-specific derived clones in Mauritius
Year of publication : 2010
Keywords : Sugarcane; breeding; selection; varieties; high biomass genotypes; characterisation; sucrose content; fibre content; fibre; biomass; inter-specific breeding ; Mauritius ;
Citation : Santchurn, D. ; Evaluation and selection of different types of sugarcane varieties for multi-purpose use from a population of inter-specific derived clones in Mauritius ; 2010
Abstract : Sugarcane is among the most efficient producers of biomass per unit area. Populations derived from crosses between sugarcane and related wild species provide a wide source of variation from which various types of canes with high biomass can be identified. To this end, the objective of this study was to characterise and identify high biomass genotypes for multiple uses from the local inter-specific derived germplasm collection. Sixty genotypes of different generations (wild, F1, BC1, BC2) were screened visually and on sucrose and fibre content from the population. They were evaluated in replicated trials with four commercial varieties used as controls. Traits of economic importance, particularly, sugar, fibre and different aboveground biomass yields were measured. Data on cane quality characters were taken at two sampling dates and characters were measured on both fresh and dry weights. The trials were followed up to the first ratoon crop. The source data were validated and few genuine outliers observed were appropriately corrected. A total of 29 parametric traits were analysed individually in each crop cycle. Results showed good reliability of the trials with coefficient of variations within the acceptable limits and good repeatability (H2) values for the majority of the traits. There was a good variation among genotypes allowing selection to operate effectively. Although precisions achievable were higher with dry weight measurements than their corresponding fresh weights, negligible differences were observed with selection simulations. It appeared that in the population of inter-specific derived clones, selection based on cane quality data collected at the pre-harvest season (April) was less efficient than those taken at early-harvest (July). Multivariate data analyses efficiently summarised the data and identified groups of similar genotypes. Principal component analysis was very helpful in visualising the existing variations in the population. Six main clusters were obtained, of which three were of economic interest. Based on inherent variations in cane quality and biomass traits, four types of canes were defined for multiple uses. From Type 1 to Type 4 canes there was a continuous progress in fibre percent. The trait was negatively correlated to sucrose content and the high fibre canes were generally thinner and taller than the commercial controls. A selection algorithm was developed that identified 11 high potential genotypes simultaneously. Biomass yields of three genotypes exceeded those of the commercial controls by 40 per cent. Fibre percent of one Type 4 cane reached 23 per cent while that of the commercial varieties fluctuated at 13 per cent. The results confirmed that high biomass varieties, with variable sucrose and fibre contents, could be obtained from the inter-specific populations. The different types of canes identified provided additional opportunities to exploit the total aboveground biomass of the crop for different end-uses, particularly for bioenergy production. The selection algorithm developed will be extended to the whole selection programme for classifying new sugarcane varieties
Source : 140 p.: 37 figs, 35 tbls;

Author : Mauritius Sugar Industry Research Institute
Title : Pest control in pitaya
Year of publication : 2010
Keywords : pitaya; pests; pest control; red ants; Solenopsis geminata; snails; Helix spp.; Giant African snail; Achatina fulica; pesticides; birds; rats ; Mauritius ;
Citation : Mauritius Sugar Industry Research Institute ; Pest control in pitaya ; 2010
Location : LIB; EXTN
Source : Recomm. Sh. Maurit. Sug. Ind. Res. Inst., 174; 2 p.

Author : Mauritius Sugar Industry Research Institute
Title : Pruning pitaya plants
Year of publication : 2010
Keywords : pitaya; cultural methods; cultivation; pruning ; Mauritius ;
Citation : Mauritius Sugar Industry Research Institute ; Pruning pitaya plants ; 2010
Location : LIB; EXTN
Source : Recomm. Sh. Maurit. Sug. Ind. Res. Inst., 175; 1 p.

Author : Khoodoo, M. H. R.; Ganoo, E. S.; Saumtally, A. S.
Title : Molecular characterization and epidemiology of Ralstonia solanacearum Race 3 biovar 2 causing brown rot of potato in Mauritius
Year of publication : 2010
Keywords : potatoes; diseases; brown rot; Ralstonia solanacearum; characterization; molecular characterization ; Mauritius ;
Citation : Khoodoo, M. H. R.; Ganoo, E. S.; Saumtally, A. S. ; Molecular characterization and epidemiology of Ralstonia solanacearum Race 3 biovar 2 causing brown rot of potato in Mauritius ; 2010
Abstract : Outbreaks of brown rot disease caused by Ralstonia solanacearum Race 3 biovar 2 have resulted in losses of 291 t of potato, worth approximately USD 171 000 since 2005 over three growing seasons. The gradual spread of this quarantine disease in Mauritius has warranted a study of the population of the pathogen. The epidemiological and ecological groupings of R. solanacearum isolated from outbreaks in Mauritius from 2005 to 2008 were examined following a study of their genetic relatedness by PCR-based marker amplified with REP and IS1112 PCR primers. The band-based genomic fingerprint data clustered strains in two major groups B and C, and one minor group A. Group B comprised exclusively of strains that caused the outbreaks in 2008 and appeared to originate from a different clonal lineage from strains clustered in groups A and C. Nucleotide polymorphisms within each group and shared markers suggest that group B strains could represent a novel introduction of the pathogen compared to the initial population of strains responsible for the outbreaks in 2005 and 2006. The clustering of strains isolated from imported ware potatoes obtained from the local market support the hypothesis that this could be a source of entry of the pathogen in Mauritius.
Location : PATH
Source : J. Phytopathol.; 158 (7-8): 503-512

Author : Saumtally, A. S.; Khoodoo, M. H. R.; Ganoo, E. S.
Title :
Year of publication : 2010
Keywords : potatoes; diseases; bacterial wilt; Ralstonia solanacearum; variations ; Mauritius ;
Citation : Saumtally, A. S.; Khoodoo, M. H. R.; Ganoo, E. S. ; ; 2010
Abstract : During October 2005, an outbreak of bacterial wilt occurred in potato varieties Atlantic, Delaware and Spunta at Britannia, in the south of the island. Symptoms on tubers were atypical of what is commonly observed with Ralstonia so/anacearum race 1 biovar 3 and consisted of profuse bacterial exudates, oozing from the eyes of tubers and extensive degradation of vascular rings. The isolated bacterium was identified as R so/anacearum race 3 biovar 2 of Andean phenotype Bv 2-A, a first report in Mauritius (1). This was confirmed by CABI Identification Service, UK. Isolates were found to metabolise the dissacharides maltose, lactose and cellobiose but not trehalose and the hexose alcohols dulcitol, mannitol and sorbitol. The pathogen is now routinely identified by PCR using race 3-specific primers 630/631 (2). The bacterium was recovered from soil samples and the alternative hosts nightshade (Solanum americanum), wild cherry tomato (Lycopersicon pimpinellifolium) and oxalis (Oxalis latifolJ) in 2006 at the first outbreak site. New outbreaks were further recorded in 2006 at Labourdonnais (north). In 2008, it was found at Belle Vue, Riche Terre, (north) and Medine (west) on potato and tomato. In the same year, it was detected in soil collected at Pamplemousses (north). In 2009, the pathogen was not observed in field samples. However, it was detected in fresh local potato tubers on sale at the market indicating that it was still present. The spread of race 3 of R so/anacearum could have a negative impact on potato cultivation and seed production in Mauritius. Due to extensive rotting of tubers, it is more damaging than race 1. In contrast to the latter, race 3 is able to thrive at a lower temperature, posing a risk to potato cultivation which takes place during the cooler months of the year in Mauritius. The pathogen has been found to survive well for over four months in infected potato tubers undergoing cool storage at 2-4 QC. The mode of entry of the new race is not known but it is suspected to have been introduced through imported ware potato as detected in 2007. Molecular studies of the population of race 3 suggest possibly different introductions as two genetically diverse groups have been characterized (3).
Location : PATH
Source : ; p. 154

Author : Dookun-Saumtally, A.; Joomun, N.; Parmessur, Y.
Title : Recent studies on phytoplasmas in Mauritius
Year of publication : 2010
Keywords : sugarcane; diseases; phytoplasmas; leaf yellows; disease detection ; Mauritius ;
Citation : Dookun-Saumtally, A.; Joomun, N.; Parmessur, Y. ; Recent studies on phytoplasmas in Mauritius ; 2010
Abstract : Bacteria lacking cell walls are classified as phytoplasmas and are associated with plant yellows diseases in several hundreds plant species. This group of microorganism cannot be cultured and this represents a major obstacle in their diagnosis and characterization by conventional means. However, with the advent of molecular diagnostic tools, detection of phytoplasmas has been greatly facilitated. In Mauritius, no phytoplasma had been reported until 1999, when one such pathogen was detected in tomato plants with bunchy top symptoms (1). Phytoplasmas have since been described in sugarcane (Saccharum hybrids), the weed Sorghum verlicilliflorum, potato and in the sugarcane delphacid Perkinsiella saccharicida. In sugarcane, leaf yellows disease is associated with sugarcane yellows phytoplasma (SCYP). The symptoms Include yellowing of the leaf midrib and leaf lamina, particularly in adult canes. Diagnosis is possible using a nested-PCR test with universal primers to amplify a 1250 bp fragment of the 16S rRNA gene of the phytoplasma. Initially, three groups of phytoplasmas were detected in sugarcane namely; Western X-16Srlll, stolbur-16Srl and coconut lethal-16SrlV (2). Mixed infection with more than one group has also been observed in some cases. Subsequently, phytoplasma DNA fragments belonging to the 16Srlll-Western X group were amplified from the sugarcane delphacid P. saccharicida, sugarcane and S. verlicilliflorum. The high sequence similarity ( 99 per cent) among fragments from sugarcane, S. verlicilliflorum and P. saccharicida indicates the possible involvement of the latter as vector of SCYP in Mauritius. Phytoplasma belonging to the aster yellows group- 16Srl has also been detected by PCR from P. saccharicida. Studies are currently ongoing to establish if P. saccharicida is a vector transmitting SCYP in sugarcane in Mauritius. Phytoplasma DNA fragments belonging to the 16Srll- tomato big bud group have also been amplified from field potato plants exhibiting little leaf symptoms and aerial tuber production (3). The importance of phytoplasmas causing plant diseases in Mauritius should be given more consideration. Now that techniques are available for their detection, a thorough survey of different crops is warranted to clarify their importance.
Location : Biotech
Source : ; p. 161

Author : Moutia, J-F. Y.; Saumtally, S.; Spaepen, S.; Vanderleyden, J.
Title : Plant growth promotion by Azospirillum sp. in sugarcane is influenced by genotype and drought stress
Year of publication : 2010
Keywords : sugarcane; varieties; variety R 570; variety M 1176/77; Azospirillum; auxins; root development; bacterial inoculation; plant growth promotion; genotypes; biological nitrogen fixation; nitrogen fixing and plant growth promoting rhizobacteria ; Mauritius ;
Citation : Moutia, J-F. Y.; Saumtally, S.; Spaepen, S.; Vanderleyden, J. ; Plant growth promotion by Azospirillum sp. in sugarcane is influenced by genotype and drought stress ; 2010
Abstract : Azospirillum influences growth and development of several crops by producing phytohormones such as auxins which have a major impact on root development. An improved root system leads to better water and nutrient uptake that in turn may influence yield positively. In this study, two agronomically contrasting sugarcane cvs R 570 and M 1176/77 adapted to different agroclimatic zones were inoculated with Azospirillum sp., with and without drought stress, to gauge how far they could benefit from this bacterial association. As early as 103 days after planting, cv M 1176/77 responded positively to inoculation with 15 per cent improved growth (shoot height) and 75 per cent more root dry mass when subjected to drought stress, whereas cv R 570 responded negatively particularly in the absence of drought stress. The significant interaction of cultivar x water regime x Azospirillum inoculation suggests a complex interplay of these factors, possibly involving the indigenous plant auxin pool. Therefore, plant genotype needs to be taken into account when recommending bacterial inoculation for direct plant growth promotion. Furthermore, enhanced growth under sub-optimal water conditions shows clearly the benefits that could be obtained in semi-arid conditions where water deficits frequently occur.
Location : LIB
Source : Pl. Soil; 337 (1-2): 233- 242

Author : Mauritius Sugar Industry Research Institute
Title : Belle Isle
Year of publication : 2010
Keywords : potatoes; variety Belle Isle ; Mauritius ;
Citation : Mauritius Sugar Industry Research Institute ; Belle Isle ; 2010
Location : LIB
Source : ; 2 p.

Author : Mauritius Sugar Industry Research Institute
Title : Sugar cane armyworms Mythimna spp.
Year of publication : 2010
Keywords : sugarcane; diseases; armyworms; Mythimna; pest control; insecticides ; Mauritius ;
Citation : Mauritius Sugar Industry Research Institute ; Sugar cane armyworms Mythimna spp. ; 2010
Source : Recommen. sh. Maurit. Sug. Ind. Res. Inst., 173; 1 p.

Author : Mauritius Sugar Industry Research Institute
Title : Fungicide treatment for the control of pineapple sett rot of sugarcane
Year of publication : 2010
Keywords : sugarcane; diseases; armyworms; Mythimna; pest control; insecticides ; Mauritius ;
Citation : Mauritius Sugar Industry Research Institute ; Fungicide treatment for the control of pineapple sett rot of sugarcane ; 2010
Source : Recommen. sh. Maurit. Sug. Ind. Res. Inst., 176; 1 p.