Postnatal Osteological Development of the Hyoid Bone in the New Zealand White Rabbit

This study augments knowledge of bone growth by observing the development of the hyoid bone in the New Zealand White rabbit. Preserved hyoid bones representing five different age periods, each period including five individuals and the total number of animals being 25, were fixed in 3.5% formaldehyde solution and 95% ethanol, followed by a pure acetone bath. They were then stained with an alcian blue–alizarin red combination. The mode of bone formation was intracartilaginous type ossification. While the basihyoideum and thyrohyoideum were observed to start ossifying first at prenatal stage, indicating that they are the main skeletal structures of the hyoid apparatus, the ceratohyoideum and lingual process began to ossify in the second and third periods. The separately occurring primary ossification centres fused completely among themselves in the fifth period. Because no further ossification centers were observed and the ossified parts continued the development and growth, the research was terminated after 10 weeks of age.     

饲料玉米的吸肥规律及其平衡施肥技术研究

为进一步提高饲料玉米的栽培水平及肥料利用率,以东陵白为试验材料,采用田间试验、室内化学分析和生物统计相结合的方法,研究了氮、磷、钾、锌肥对饲料玉米N、P、K养分吸收及产量形成的影响。主要结果是: (1)分析说明了饲料玉米在生育进程中全株N、P、K的浓度、吸收累积量、吸收速率等变化规律及与施肥的关系,提供了每1000kg干草需要吸收N、P、K、Fe、Mn、Cu、Zn的数量;(2)应用一元三次方程模拟了不同施肥条件下干物质和N、P、K养分吸收量与出苗后天数之间的回归关系,明确了干物质和N、P、K养分吸收的最快速率及出现时间;(3)氮、磷、钾化肥可显著提高饲料玉米鲜草产量,氮肥增产50.2%,磷肥增产36.4%,钾肥增产13.2%。     

The effect of temperature during growth and flowering on the seed set of tetraploid freesia

Summary Phytotron experiments have been carried out to study the effect of different temperatures on the seed set of tetraploid freesias during the raising of the plants and at the time of flowering and pollination.The effect of a relatively low temperature during the growth period is reflected in a comperatively greater number of flowers as a result of an increase in number of ramifications of the peduncle. This sometimes promotes the seed yield notwithstanding that the lower temperature reduces the fertility of each seperate flower. It is clearly proved that the temperature during flowering and pollination affects the fertility of the flower and the ultimate seed yield of the plant. Experiments in our phytotron showed 14°C during the growth period and 20°C at the time of pollination to be the optimum combination for a good seed yield.The effect of a lower night temperature was generally favourable, particularly so when measured by the number of seeds per pollinated flower.     

RAPD genetic diversity of Albanian olive germplasm and its relationships with other Mediterranean countries

RAPD markers were used for the study of 19Albanian olive cultivars and two wild olives (oleasters). A total of 76polymorphic bands (4.8 polymorphic markers per primer) out of 107 reproducible were obtained using 16 primers. The number of bands per primer ranged from 4 to 10,whereas the number of polymorphic bands ranged from 1 to 9, corresponding to 71%of the total amplification products. All the accessions could be identified by the combination of four primers: OPA-19;OPA-02; OPK-16 and OPP-19. The dendrogram,based on Jaccard's index, included three major groups according to their origin: 1)most of the cultivars from the area of Berat (South of Albania) 2) cultivars from the Centre and Centre-North of Albania and3) cultivars from the Centre and North-West of Albania along with the oleaster from Elbasan. In order to evaluate the origin of Albanian cultivars they were compared to those diffused in other countries like Greece, Italy and Turkey, due to geographical and historical affinity among these countries, by using a one way AMOVA. Although most of the genetic diversity was attributable to differences among cultivars within each country (91.47%) significantφ-values among countries(φ_st = 0.085; p < 0.001)suggested the existence of RAPD phenotypic differentiation. Significant φ-values in all pairs formed by Albania with the other countries were observed. These results are consistent with the autochthonous origin of Albanian cultivars. This revised version was published online in August 2006 with corrections to the Cover Date.     

Selection of wheat based on economic returns per unit area

This study aimed to investigate a cultivar selection criterion based on income ha⁻¹ in common wheat. Regional yield trials with 20 entries were planted in Diyarbakır, Hazro and Ceylanpınar in southeast Anatolia in the 2004/2005 growing season. A randomized complete block design with four replications was employed. Grain samples from each location were subjected to quality analyses, and then presented to randomly selected grain purchasers with the local commodity market for market price estimations. Entries 1, 9, 10, 7 and 6 were the top five ranking entries for grain yield, giving 5,320, 5,290, 5,280, 5,140 and 5,130 kg ha⁻¹, respectively. From the market price perspective, entries 17, 3, 7, 20 and 8 received the five highest marketing price offers with the values 239.0, 238.1, 237.1, 236.9 and 236.7 US$ tonne⁻¹, respectively. There was a US$ 10.94 tonne⁻¹ market price difference between entries with the highest and the lowest market price. The only quality analyses showing significant correlations with market price were Zeleny sedimentation value and hectolitre weights (kg hl⁻¹). From thev production income [= marketing price (US$ tonne⁻¹) × grain yield (kg ha⁻¹)] point of view, entries 9, 10, 1, 7 and 6 were ranked from 1st to 5th for production income ha⁻¹ with the values 1,241.0, 1,238.0, 1,219.9, 1,214.2 and 1,209.3 US$ ha⁻¹, respectively. All five high yielding entries were also high-income entries. A rank stability analysis further indicated that entry numbers 6, 7, 8, 4 and 1 stable for high production income ha⁻¹. A simulation study, based on allocation of additional premiums for high quality indicated that entries 9,1,10, 7, and 6 would be top ranking for high income ha⁻¹ if given an additional premium of as much as twice the standard deviations of market price for each entry (the highest premium limit; 20.24 US$ tonne⁻¹). The order for cultivar preference for high production income ha⁻¹ would change and would generate 1,321.94, 1,296.20, 1,281.11, 1,258.06 and 1,243.01 US$ ha⁻¹, respectively. It was concluded that the relatively quality conscious Şanlıurfa commodity market does not offer adequate premiums for the high quality grains. This results in farmer preference for high yielding lower quality cultivars. Even though quality cannot be neglected, and cultivar preference could change with additional premiums, breeders must give more attention to high production income ha⁻¹.     

Genetic variability measures among Bromus catharticus Vahl. populations and cultivars with RAPD and AFLP markers

The objectives of this study were to optimize RAPD and AFLP techniques in B. catharticus, and to determine the genetic variability of populations and commercial prairie grass cultivars with the aforementioned molecular markers. Two populations with contrasting morphological characteristics were evaluated from individual and bulked DNA samples using RAPD markers. Both analyses showed a similar information about inter population variability. Each accession was sampled by a single leaf bulk of 10 plants. Accession similarities were established with 276 RAPD and 714 AFLP bands using Jaccard similarity coefficient. The dendrogram of the accessions using RAPD markers showed that they shared high similarity values (>94%). A similar result was obtained with AFLP markers (similarity values >98%), revealing a narrow genetic basis in the analyzed accessions. Consequently, molecular characterization of germplasm should be considered in addition to morphological criteria, to choose the parental genotypes for breeding programs of this forage crop. The AFLP technique was more efficient to detect DNA polymorphism in our experiments and unique fingerprints were detected for all the accessions. RAPD is a simple and non expensive technique, suitable to estimate genetic similarity. This revised version was published online in August 2006 with corrections to the Cover Date.     

Ecuador, 1991 potato germplasm collecting expedition: taxonomy and new germplasm resources

Summary We conducted a joint Ecuador/Colombia/United States wild potato (Solanum sect. Petota) germplasm collecting expedition in Ecuador from April 13–July 1, 1991. The goals of the expedition were to collect germplasm and study the species boundaries of all of the 25 Ecuadorian taxa accepted by current taxonomists. We made 126 collections of 24 of these 25 taxa, 113 as germplasm samples, 13 only as herbarium collections. We synonymize six of these 25 names (S. baezense Ochoa, S. cyanophyllum Correll, S. pichinchense Bitter & Sodiro, S. serratoris Ochoa, S. suffrutescens Correll as synonyms of S. andreanum Baker; S. correllii Ochoa as a synonym of S. regularifolium Correll). Four other names (S. chomatophilum f. angustifoliolum Correll, S. moscopanum Hawkes, S. solisii Hawkes, S. tundalomense Ochoa) could not be consistently distinguished from S. colombianum Dunal in the field. We are currently investigating them to determine their species status.     

Genetics of resistance to 3 isolates of Ascochyta fabae on Faba bean (Vicia faba L.) in controlled conditions

Summary Genetics of resistance to Ascochyta fabae Speg. in Vicia faba L. was studied with a final objective to develop resistant faba bean varieties to Ascochyta blight. The study was conducted separately on 3 single spore isolates (AF10-2 and AF13-2 from Tunisia and AF4-3 from France) and belonging to different groups of virulence (GV1 and GV2). Important general combining ability (GCA) effects were found especially with isolates AF10-2 and AF4-3. Specific combining ability (SCA), although significant for the 3 isolates, was important only with AF13 -2, but less important than GCA. Additive gene effects were predominant to non-additive effects. Lines 29H and A8817 transmitted to their progenies resistance to the 3 isolates, whereas 14–12 and 19TB conferred resistance to their progenies only with isolates AF13-2 and AF4-3, respectively. In the material studied, resistance was generally controlled by dominant genes but also could be attributed to recessive genes although less frequent. Analysis of segregation in the F2 of 2 crosses between the resistant lines (A8817 and 29H) and the susceptible line (14–12) with isolate AF4-3 revealed dominant monogenic control at the level of leaves in the 2 resistant lines and, in addition, a recessive gene controlling resistance of stems. Non-allelic interactions were occasionally manifested and their origin appeared to be due to line 19TB. A recurrent selection scheme was proposed with the objective to develop improved open-pollination populations and synthetic varieties responding to the objective of the national Tunisian research programme on faba bean.