Showing 5 results for Breeding
M. Mostajeran, M. A. Edriss, R. Ebadi, G. H. Tahmasebi,
Volume 4, Issue 1 (4-2000)
Abstract
In order to estimate the heritability of morphological characters of worker honey bee and honey yield, 30 queen-mothers were selected randomly from the apiary of Research Center of Animal Science and Natural Resources in Isfahan Province. From each queen-mother, five queen-daughters were reared and introduced to equalize colonies after natural mating of queens. Summer honey yield was measured, while fall honey production was calculated from area of sealed honey combs. The total honey was calculated by adding summer honey production to fall honey production. Morphological characters were measured under a stereo-dissecting microscope fitted with a calibrated micrometer reticle according to Ruttners method (1985).
Heritabilities were estimated by intraclass correlation method. Heritabilities of summer, fall and total yearly honey yields were estimated to be 0.64, 0.51 and 0.30, respectively. Estimates of heritability of morphological characters for probscis length, tibia length, femur length, metatarsus length, metatarsus width, forewing length, forewing width, cubital index, hindwing length and number of hamuli were 0.64±0.08, 0.45±0.07, 0.50±0.07, 0.47±0.07, 0.33±0.06, 0.42±0.06, 0.89±0.10, 0.5±0.07, 0.94±0.10 and 0.45±0.07, respectively. It could be concluded that in order to increase honey yield in either season (summer or fall), selection must be based on the amount of honey yield in the corresponding season. Thus, heritabilities of forewing and hindwing lengths were high selection according to these morphological characters would, therefore, change the size of these characters.
I. Malek Mohammadi, A. Shafii Alavijeh,
Volume 4, Issue 2 (7-2000)
Abstract
Mutual understanding among officials and followers has been a point of concern in behavioral management. Natural resources extension which, from the very first step, is concerned with the exploration of practical problems is in serious need of an atmosphere of mutual understanding between agents and clientele. In this research, attention was drawn toward the measurement of mutual understanding between executives and nomads regarding nomads’ problems in utilizing natural resources and breeding cattle in Isfahan Province. For this purpose, initially, understanding between nomads and natural resources administrators (extension agents and specialists) regarding their respective problems were measured and compared. The research population of the study consisted of two groups. The first, involved 32 administrators, extension agents and specialists, and the second, 75 nomad families. Two different questionnaires were developed for the study as research instruments in which 52 items regarding nomad problems were included. Each part of the population was asked to rank the items accordingly. Then, some nonparametric tests such as Kruscall Wallis and Mann Whitny U tests were applied to compare the mean rank for each item within and between the two groups.
Results showed that the administrators and nomads had different attitudes in only two of the 52 items. Administrators had no statistically significant different attitude in 52 problems. Eliminating the discriminating items, the attitudes in only two groups were compared and results showed that they had no significant difference in the remaining 48 items. Therefore, extension agents can follow these problems based on their mean rank priority in their developmental projects. This method of data reduction and understanding field constraints can be applied to the studies dealing with planning agricultural and/or natural resources development projects through extension education.
M. Moradi, A.m. Rezai, A. Arzani,
Volume 11, Issue 42 (1-2008)
Abstract
Evaluation of genetic improvement of grain yield and other traits in cultivars released in different years is useful to determine plant breeding impact on grain yield improvement, to define future selection criteria and to identify the desirable environment and traits for further assessment. This study was conducted to evaluate the genetic improvement for grain yield and other traits of twelve oat (Avena sativa L.) cultivars released in Canada during 1921- 1997, at Research Farm, College of Agriculture, Isfahan University of Technology, during 2001-3 in a randomized complete block design with three replications. The regression of mean grain yield on released year of the cultivars showed that the rate of increase in grain yield during a 76-year period is 32.63 kg h-1 year-1 or 0.63% per year. Breeding programmes have inereased harvest index, grain number per panicle and fertile tillers /m2. The effort of breeders in this period was to decrease plant height and days to heading. The other traits had small changes and showed no specific trends. In general the results of this study showed continous improvement of grain yield in this period. Genetic improvement of grain yield in evaluated cultivars closely correlated with harvest index. Therefore, most variation in grain yield of oats was due to variation in harvest index. Although much of the improvement in grain yield described here could be attributed to the increased harvest index, the scope for further improvement in this character may be limited. Further yield improvement of oats might be achieved by combining high biological yield with high harvest index.
J. Erfani Moghaddam, A. Ebadi, M. Fatahi Moghaddam,
Volume 12, Issue 45 (10-2008)
Abstract
Seedlessness is the most important characteristic of fruit quality for raisin and table grapes. Grape breeding at University of Tehran, Karaj branch, Iran started in 1999 with crossing some selected seedless and seeded cultivars at the end of evaluation of 90 cultivars in grapevine collection of College of Agriculture in Karaj. Out of 1400 progeny obtained from 26 different crosses, 381 of them which produced fruits were evaluated during growing seasons of 2006 & 2007. Progenies were divided into four groups of completely seedless, semi-seedless, semi-seeded and completely seeded, according to seed trace or seed weight. Results classified progeny to 11% completely seedless, 13.6% semi-seedless, 24% semi seeded and 51.2% completely seeded. Percentages of seedless progeny for four male parents of Askary, Yaghooti, Bidane Sefid and Bidane Ghermez were 15.4%, 10.8%, 9.3% and 10.6%, respectively. Meanwhile, percentages of seedless progeny for female parents of Muscut of Hamburg, Ghezel Uzum, Dizmary, Rajabi Sefied, Ali Baba, Alhaghi Ghermez and Tabariz were 5.4%, 5%, 17.5%, 13.2 %, 1.4%, zero and 36%, respectively. Results also showed that among male parents, Yaghooti and Bidane Ghermez cultivars and among female parents, Tabarze cultivar had better backgrounds to transmit stenospermocarpic seedlessness characteristics.
A Gharghni, A Talei, Z Zamani, M Fatahi Moghadam, H Haj Najari, S Gardiner,
Volume 13, Issue 48 (7-2009)
Abstract
A population of offspring from a cross between ‘Golden Smoothee’ × ‘Shafi Abadi’ apple which was developed by two methods of controlled pollination (with and without covering after controlled pollination) was used to investigate the inheritance of microsatellite alleles and the necessity of covering in controlled pollination of apple. DNA was extracted from 60 seedlings (30 from each method) as well as corresponding parents and the probable source of unwanted pollen. Four microsatellite loci (CH03d12, CH03d07, CH04a12 and CH03c07) which were polymorphic among parents were selected and their florescent primers were prepared. DNA amplification was carried out using different colored florescent primers, and alleles size were determined using ABI377 automatic gene sequencer and Gene Scan Software version 2.0 according to internal standards. Results showed that all seedlings shared one allele at each locus with each parent indicating their hybrid and true to type nature. There were no differences between two methods of controlled pollination in terms of unwanted pollination and there were no off type seedling originating from unwanted pollen source. Allele distribution among the progenies showed their co-dominant mode of inheritance, and no significant difference with Mendelian co-dominant ratio (1:1:1:1) was observed using chi square (x2) test. These results showed that there was no need for covering after controlled pollination of apple at least for less sensitive cases such as cultivar breeding which takes lots of time and cost for controlled pollination of many flowers in a limited time span. Results also showed the importance and potential of microsatellite loci in detecting parent-offspring relationship prior to inheritance study of characters and alleles, bulk segregation analysis, gene and linkage map and historical reconstruction of fruit tree pedigree.
