In stratified random sampling when several characteristics are to be estimated simultaneously, an allocation that is optimum for one characteristic may be far away from optimum for others. To resolve this conflict the authors formulate the problem of determining optimum compromise allocation as a nonlinear programming problem (NLPP). The allocation obtained is optimum in the sense that it minimizes the sum of weighted variances of the estimated population means of the characteristics subject to a fixed sampling cost. The formulated NLPP is treated as multistage decision problem and solved using dynamic programming technique. A numerical example is presented to illustrate the computational details.
{"title":"A note on optimum allocation in multivariate stratified sampling","authors":"M. G. Khan, M. J. Ahsan","doi":"10.1071/SP03017","DOIUrl":"https://doi.org/10.1071/SP03017","url":null,"abstract":"In stratified random sampling when several characteristics are to be estimated simultaneously, an allocation that is optimum for one characteristic may be far away from optimum for others. To resolve this conflict the authors formulate the problem of determining optimum compromise allocation as a nonlinear programming problem (NLPP). The allocation obtained is optimum in the sense that it minimizes the sum of weighted variances of the estimated population means of the characteristics subject to a fixed sampling cost. The formulated NLPP is treated as multistage decision problem and solved using dynamic programming technique. A numerical example is presented to illustrate the computational details.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123379872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Seeds from a toxic variety of Jatropha curcas (Capo Verde, Nicaragua) were processed, defatted and ground to obtain the meal. The meal was subjected to heat and 14 different chemical treatments to detoxify the meal of lectin and phorbolesters. Heat treatment inactivated lectin, but not phorbolester. One of the treatments reduced phorbolesters to a tolerable level of 0.09 mg/g. The treated meals with other ingredients were used in diets to assess acceptance and nutritive value of detoxified Jatropha curcas meal in two experiments. Experiments 1 and 2 had twelve (12) male weanling rats each, Sprague Dawley strain, 28-30 days old, pre-experimental average body weights of 8379±7.2 and 84.6±6.4 g, respectively. They were divided into three groups according to body weight and fed casein diet (control) and two diets in which Jatropha curcas was the protein source. In experiment 1, the rats accepted diet 1, but did not fully accept diet 2. Food intake, growth rate, protein efficiency ratio (PER) and food transformation index (T1) were significantly better (P<0.05) in diet 1 than in the casein and diet 2. In experiment 2, casein diet was better (P<0.05) in food intake, growth rate, PER and TI than diets 1 and 2. Food intake with Jatropha meal was significantly reduced and the rats had drastic body weight loss (P<0.05) and this might be due to the presence of phorbolesters in the diets. Generally, the presence of phorbolesters in food has significant effect on its acceptance. Jatropha meal obtained from treatment 3 had a crude protein (CP) content of 68%, far higher than the CP content of most oilseed meals (soyabean). This treatment seems a better method of detoxifying Jatropha curcas meal for livestock but in economic terms it is expensive to produce a meal from it.
{"title":"Detoxification of a toxic variety of Jatropha curcas using heat and chemical treatments, and preliminary nutritional evaluation with rats","authors":"E. M. Aregheore, K. Becker, H. Makkar","doi":"10.1071/SP03010","DOIUrl":"https://doi.org/10.1071/SP03010","url":null,"abstract":"Seeds from a toxic variety of Jatropha curcas (Capo Verde, Nicaragua) were processed, defatted and ground to obtain the meal. The meal was subjected to heat and 14 different chemical treatments to detoxify the meal of lectin and phorbolesters. Heat treatment inactivated lectin, but not phorbolester. One of the treatments reduced phorbolesters to a tolerable level of 0.09 mg/g. The treated meals with other ingredients were used in diets to assess acceptance and nutritive value of detoxified Jatropha curcas meal in two experiments. Experiments 1 and 2 had twelve (12) male weanling rats each, Sprague Dawley strain, 28-30 days old, pre-experimental average body weights of 8379±7.2 and 84.6±6.4 g, respectively. They were divided into three groups according to body weight and fed casein diet (control) and two diets in which Jatropha curcas was the protein source. In experiment 1, the rats accepted diet 1, but did not fully accept diet 2. Food intake, growth rate, protein efficiency ratio (PER) and food transformation index (T1) were significantly better (P<0.05) in diet 1 than in the casein and diet 2. In experiment 2, casein diet was better (P<0.05) in food intake, growth rate, PER and TI than diets 1 and 2. Food intake with Jatropha meal was significantly reduced and the rats had drastic body weight loss (P<0.05) and this might be due to the presence of phorbolesters in the diets. Generally, the presence of phorbolesters in food has significant effect on its acceptance. Jatropha meal obtained from treatment 3 had a crude protein (CP) content of 68%, far higher than the CP content of most oilseed meals (soyabean). This treatment seems a better method of detoxifying Jatropha curcas meal for livestock but in economic terms it is expensive to produce a meal from it.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114805437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A four-month study of the attenuation measurement on satellite TV transmission down link is reported. The time percentage distributions of the attenuation show a fairly large month-to month variation. However, such variations seem to be closely related to the variation of the rain-rate distribution. Comparison of exceedance and the cumulative rainfall during these four months with those of the ten -year data indicates a similar variation this year. Measurements on a “cloudy” day without any rain indicate that the attenuation by cloud is small.
{"title":"Preliminary findings of the effect of some atmospheric parameters on Ku-band satellite link.","authors":"V. Ramachandran, Vickal V. Kumar","doi":"10.1071/SP03012","DOIUrl":"https://doi.org/10.1071/SP03012","url":null,"abstract":"A four-month study of the attenuation measurement on satellite TV transmission down link is reported. The time percentage distributions of the attenuation show a fairly large month-to month variation. However, such variations seem to be closely related to the variation of the rain-rate distribution. Comparison of exceedance and the cumulative rainfall during these four months with those of the ten -year data indicates a similar variation this year. Measurements on a “cloudy” day without any rain indicate that the attenuation by cloud is small.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"151 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116520118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sea urchins are major substratum eroders of coral reefs and the calcium carbonate condition of coral reefs may therefore reflect the abundance of sea urchins. The omnivorous urchins, Echinometra spp. are known as “rock -borers” and are agents of large-scale bioerosion, particularly in the Caribbean, Eastern Pacific and Western Indian Ocean. By burrowing into coral rocks they protect themselves from predators, wave and current action, and to some extent from desiccation at low tide. Bioerosion estimates are known for a few specific reefs only. Although the Echinometra sp. A have not been named yet, they were mistaken for Echinometra mathaei for long in Fiji. This novel study attempted to estimate bioerosion rates of the low but consistent numbers of sea urchins, Echinometra sp. A (green-white-tipped) on the Nukubuco reef, Fiji by calculation of the net carbonate accumulation. Cage experiments reported bioerosion rates (kg CaCO3/m2/urchin/d) of 35-37 x 10-3 at the reef crest and 30-43 x 10-3 at the reef flat. This method of assessing bioerosion showed both strengths and weaknesses. However, the Nukubuco reef balance between reef growth and reef destruction is shifting, with bioerosion becoming the dominant process.
海胆是珊瑚礁主要的基质侵蚀者，珊瑚礁的碳酸钙状况可以反映海胆的丰度。杂食性海胆，Echinometra spp.被称为“岩石蛀虫”，是大规模生物侵蚀的代理人，特别是在加勒比海，东太平洋和西印度洋。通过钻入珊瑚岩石，它们可以保护自己免受捕食者、海浪和水流的影响，在一定程度上还可以避免退潮时的干燥。已知的生物侵蚀估计只针对少数特定的珊瑚礁。尽管棘足虫sp. A尚未被命名，但在斐济长期被误认为是棘足虫。这项新颖的研究试图通过计算净碳酸盐积累来估计斐济努库布科礁上数量不多但数量一致的海胆(绿白尖)的生物侵蚀速率。笼试验报告的生物侵蚀速率(kg CaCO3/m2/海胆/d)在礁顶为35-37 x 10-3，在礁滩为30-43 x 10-3。这种评估生物侵蚀的方法既有优点也有缺点。然而，努库布科珊瑚礁生长和破坏之间的平衡正在发生变化，生物侵蚀成为主导过程。
{"title":"A Novel Method of Assessing Bioerosion by the Sea Urchin Echinometra sp. A on a Fijian Reef","authors":"S. Appana, V. Vuki","doi":"10.1071/SP03005","DOIUrl":"https://doi.org/10.1071/SP03005","url":null,"abstract":"Sea urchins are major substratum eroders of coral reefs and the calcium carbonate condition of coral reefs may therefore reflect the abundance of sea urchins. The omnivorous urchins, Echinometra spp. are known as “rock -borers” and are agents of large-scale bioerosion, particularly in the Caribbean, Eastern Pacific and Western Indian Ocean. By burrowing into coral rocks they protect themselves from predators, wave and current action, and to some extent from desiccation at low tide. Bioerosion estimates are known for a few specific reefs only. Although the Echinometra sp. A have not been named yet, they were mistaken for Echinometra mathaei for long in Fiji. This novel study attempted to estimate bioerosion rates of the low but consistent numbers of sea urchins, Echinometra sp. A (green-white-tipped) on the Nukubuco reef, Fiji by calculation of the net carbonate accumulation. Cage experiments reported bioerosion rates (kg CaCO3/m2/urchin/d) of 35-37 x 10-3 at the reef crest and 30-43 x 10-3 at the reef flat. This method of assessing bioerosion showed both strengths and weaknesses. However, the Nukubuco reef balance between reef growth and reef destruction is shifting, with bioerosion becoming the dominant process.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122391790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To see if there is a significant difference between the performance of the first year (100 level) students at the University of the South Pacific (USP) having different Form Seven marks, a statistical analysis is carried out using their Cumulative Grade Point Averages (CGPA). For this analysis, relevant data was obtained for the years 1997-2001 and the Form Seven marks (Total of English and best 3 subjects) were divided into the classes 250 – 259, 260 – 269, and ≥ 270. Results indicate that there is a significant difference between the CGPA of these three classes. A further analysis is then carried out by using the CGPA of only the first two classes 250 – 259 and 260 – 269 in order to determine if an increase in the entry requirements from 250 to 260 will be justified. Under its current admission regulations, USP accepts into its degree programmes all students who have passed the seventh form examination with an aggregate of at least 250 marks out of 400 with a minimum of 50% in English. The results of our analysis indicate that the minimum entry requirement could be increased to 260 if USP feels that the level of significance (Type 1 Error) is more than 3.17 percent. However, the minimum entry level should remain as 250 if the significance level is at most 3.17 percent.
{"title":"Study of performance of first year USP students with respect to their form seven marks","authors":"U. J. Dixit, M. Reddy","doi":"10.1071/SP02009","DOIUrl":"https://doi.org/10.1071/SP02009","url":null,"abstract":"To see if there is a significant difference between the performance of the first year (100 level) students at the University of the South Pacific (USP) having different Form Seven marks, a statistical analysis is carried out using their Cumulative Grade Point Averages (CGPA). For this analysis, relevant data was obtained for the years 1997-2001 and the Form Seven marks (Total of English and best 3 subjects) were divided into the classes 250 – 259, 260 – 269, and ≥ 270. Results indicate that there is a significant difference between the CGPA of these three classes. A further analysis is then carried out by using the CGPA of only the first two classes 250 – 259 and 260 – 269 in order to determine if an increase in the entry requirements from 250 to 260 will be justified. Under its current admission regulations, USP accepts into its degree programmes all students who have passed the seventh form examination with an aggregate of at least 250 marks out of 400 with a minimum of 50% in English. The results of our analysis indicate that the minimum entry requirement could be increased to 260 if USP feels that the level of significance (Type 1 Error) is more than 3.17 percent. However, the minimum entry level should remain as 250 if the significance level is at most 3.17 percent.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124425859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
New results on graph theoretical method of encryption will be presented. The general idea is to treat vertices of a graph as messages, and walks of a certain length as ecnryption tools. We will construct one-time pad algorithms with a certain resistance to attacks when the adversary knows plaintext and ciphertext. Special linguistic graphs of high girth whose vertices (messages) and walks (encoding tools) could be both naturally identified with vectors over the finite field, and with the so-called parallelotopic graphs, which turn out to be efficient tools for symmetric encryption. We will formulate criteria when parallelotopic graph (or the more general graph of tactical configuration) is a graph of absolutely optimal encryption scheme, producing asymptotic one-time pad algorithm. We will show how to convert one-time pads, which are related to geometries of rank 2 of simple groups of Lie type, to a real-life encryption scheme involving potentially infinite text and flexible passwords. We will discuss families of linguistic and parallelotopic graphs of increasing girth as the source for the generation of asymmetric cryptographic functions and related open key algorithms. We will construct new families of such graphs via group theoretical and geometrical technique. The software for symmetric and asymmetric ecnryption (prototype model of the package) is ready for demonstration.
{"title":"Walks on graphs as symmetric or asymmetric tools to encrypt data","authors":"V. Ustimenko, Y. Khmelevsky","doi":"10.1071/SP02008","DOIUrl":"https://doi.org/10.1071/SP02008","url":null,"abstract":"New results on graph theoretical method of encryption will be presented. The general idea is to treat vertices of a graph as messages, and walks of a certain length as ecnryption tools. We will construct one-time pad algorithms with a certain resistance to attacks when the adversary knows plaintext and ciphertext. Special linguistic graphs of high girth whose vertices (messages) and walks (encoding tools) could be both naturally identified with vectors over the finite field, and with the so-called parallelotopic graphs, which turn out to be efficient tools for symmetric encryption. We will formulate criteria when parallelotopic graph (or the more general graph of tactical configuration) is a graph of absolutely optimal encryption scheme, producing asymptotic one-time pad algorithm. We will show how to convert one-time pads, which are related to geometries of rank 2 of simple groups of Lie type, to a real-life encryption scheme involving potentially infinite text and flexible passwords. We will discuss families of linguistic and parallelotopic graphs of increasing girth as the source for the generation of asymmetric cryptographic functions and related open key algorithms. We will construct new families of such graphs via group theoretical and geometrical technique. The software for symmetric and asymmetric ecnryption (prototype model of the package) is ready for demonstration.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126296518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Using four 100 × 10 m transects, the coastal vegetation types and their horizontal stratification at Taunovo Bay, Pacific Harbour, were investigated. The common stratification pattern of herb zone, shrub zone (dominated by the invasive species Chrysobalanus icaco) and tree zone was observed. Littoral forest composed of species commonly associated with sandy beaches and species commonly associated lowland rainforest was observed. This vegetation type is here reported for the first time from Fiji and is probably caused by siliceous deposits from a nearby river. A detailed study of the extend, composition and distribution of this unique vegetation type should be conducted before the development project (planned at the study site) is approved.
{"title":"Coastal Vegetation of Taunovo Bay, Pacific Harbour, Viti Levu, Fiji - A Proposed Development Site","authors":"G. Keppel","doi":"10.1071/SP02006","DOIUrl":"https://doi.org/10.1071/SP02006","url":null,"abstract":"Using four 100 × 10 m transects, the coastal vegetation types and their horizontal stratification at Taunovo Bay, Pacific Harbour, were investigated. The common stratification pattern of herb zone, shrub zone (dominated by the invasive species Chrysobalanus icaco) and tree zone was observed. Littoral forest composed of species commonly associated with sandy beaches and species commonly associated lowland rainforest was observed. This vegetation type is here reported for the first time from Fiji and is probably caused by siliceous deposits from a nearby river. A detailed study of the extend, composition and distribution of this unique vegetation type should be conducted before the development project (planned at the study site) is approved.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127636049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Timetabling is a difficult (NP-complete) problem and belongs to a general class of problems known as scheduling. Due to a variety of constraints typical in different timetabling environments, it has been difficult to develop a generic solution for timetabling. This paper is an attempt to define a generic computational model for examination timetabling for predefined constraints found in the problem, and proposes a heuristic method of developing an acceptable solution. The declarative nature of the developed constraints language (based on the structured query language) is utilized to construct constraints and specify the timetabling problem as a constraint satisfaction problem. A university examination timetabling problem is used to illustrate and test the model.
{"title":"A Heuristic Approach to Constraint Optimization in Timetabling","authors":"A. Chand","doi":"10.1071/SP02013","DOIUrl":"https://doi.org/10.1071/SP02013","url":null,"abstract":"Timetabling is a difficult (NP-complete) problem and belongs to a general class of problems known as scheduling. Due to a variety of constraints typical in different timetabling environments, it has been difficult to develop a generic solution for timetabling. This paper is an attempt to define a generic computational model for examination timetabling for predefined constraints found in the problem, and proposes a heuristic method of developing an acceptable solution. The declarative nature of the developed constraints language (based on the structured query language) is utilized to construct constraints and specify the timetabling problem as a constraint satisfaction problem. A university examination timetabling problem is used to illustrate and test the model.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124105362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The University of the South Pacific (USP is currently attracting many students who have completed a Diploma at the Fiji College of Advanced Education (FCAE) into its study programmes. These students are not required to do certain courses, mostly those at the first year level, as they had done courses of a similar nature at FCAE and hence these are cross-credited towards their study programme as USP. In order to ensure that the granting of cross-credits for these FCAE courses is justified, USP needs to study the performance of these students. In this paper, we have carried out a statistical analysis using the Cumulative Grade Point Averages (CGPA) of all 67 such students. Results of the analysis indicate that the performance of these students justifies the granting of cross-credits.
{"title":"Performance of FCAE diploma holders at USP","authors":"U. J. Dixit, V. U. Dixit, M. Reddy","doi":"10.1071/SP02012","DOIUrl":"https://doi.org/10.1071/SP02012","url":null,"abstract":"The University of the South Pacific (USP is currently attracting many students who have completed a Diploma at the Fiji College of Advanced Education (FCAE) into its study programmes. These students are not required to do certain courses, mostly those at the first year level, as they had done courses of a similar nature at FCAE and hence these are cross-credited towards their study programme as USP. In order to ensure that the granting of cross-credits for these FCAE courses is justified, USP needs to study the performance of these students. In this paper, we have carried out a statistical analysis using the Cumulative Grade Point Averages (CGPA) of all 67 such students. Results of the analysis indicate that the performance of these students justifies the granting of cross-credits.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117328786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fruits from hermaphrodite Hawaiian varieties are of medium size and preferred by consumers all over the world. Seeds obtained from the fruits of selfed hermaphrodite plants produce almost two third hermaphrodite plants and one-third pistillate plants. These plants can not be identified before the onset of flowering. However, there are conflicting reports in scientific literature on sex ratios obtained from selfed seeds from fruits of hermaphrodite plants. Sex ratios of hermaphrodite, pistillate and staminate plants were determined using seeds from selfed hermaphrodite fruits of a Hawaiian papaya (Carica papaya) variety ‘solo’. Bagging flowers on hermaphrodite plants during flowering season to avoid contamination from foreign pollen produced self-seeds. Seeds from fruits of many bagged hermaphrodite flowers were pooled together and grown in large plots. A total of 2633 plants were grown and evaluated for their specific sex at the onset of flowering. Of these 1838 were counted as hermaphrodite, 783 pistillate and only 12 staminate plants. This gave a ratio of 2.34 hermaphrodite plants : 1: pistillate plants ignoring 12 staminate plants. This obtained ratio is in disagreement with earlier reported ratio of 2 hermaphrodite plants : 1 pistillate : 1 non-viable zygotes. However, no viable male progeny was reported from hermaphrodite selfed seeds in earlier studies. One of the explanations for the observed changed ratio could be biased seed selection from the seed lot used for planting.
{"title":"Sex Ratio in Hawaiian Papaya (Carica papaya L.) Variety ‘Solo’","authors":"Shafiya Khan, A. Tyagi, A. Jokhan","doi":"10.1071/SP02005","DOIUrl":"https://doi.org/10.1071/SP02005","url":null,"abstract":"Fruits from hermaphrodite Hawaiian varieties are of medium size and preferred by consumers all over the world. Seeds obtained from the fruits of selfed hermaphrodite plants produce almost two third hermaphrodite plants and one-third pistillate plants. These plants can not be identified before the onset of flowering. However, there are conflicting reports in scientific literature on sex ratios obtained from selfed seeds from fruits of hermaphrodite plants. Sex ratios of hermaphrodite, pistillate and staminate plants were determined using seeds from selfed hermaphrodite fruits of a Hawaiian papaya (Carica papaya) variety ‘solo’. Bagging flowers on hermaphrodite plants during flowering season to avoid contamination from foreign pollen produced self-seeds. Seeds from fruits of many bagged hermaphrodite flowers were pooled together and grown in large plots. A total of 2633 plants were grown and evaluated for their specific sex at the onset of flowering. Of these 1838 were counted as hermaphrodite, 783 pistillate and only 12 staminate plants. This gave a ratio of 2.34 hermaphrodite plants : 1: pistillate plants ignoring 12 staminate plants. This obtained ratio is in disagreement with earlier reported ratio of 2 hermaphrodite plants : 1 pistillate : 1 non-viable zygotes. However, no viable male progeny was reported from hermaphrodite selfed seeds in earlier studies. One of the explanations for the observed changed ratio could be biased seed selection from the seed lot used for planting.","PeriodicalId":148381,"journal":{"name":"The South Pacific Journal of Natural and Applied Sciences","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128094547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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