Delimitation ofPelargonium sect.Glaucophyllum (Geraniaceae)

Pelargonium otaviense Knuth andP. spinosum Willd. are excluded from sect.Glaucophyllum, whileP. grandiflorum (Andr.)Willd.,P. patulum Jacq. andP. tabulare (Burm. f.)L'Hérit. of sect.Eumorpha are included. Sect.Glaucophyllum is characterized by green to glaucous vegetative organs and zygomorphic white to pink corolla with five narrow petals. All the species have an identical pollen and chromosome morphology, the same basic chromosome number (x = 11) and similar flavonoid patterns. A close relationship between sect.Glaucophyllum and sect.Pelargonium is indicated by the occurrence of natural hybrids and concordant characters. Isorhamnetin and luteolin have been detected in the genus for the first time.     

Breeding program for the lesser kudu (Tragelaphus imberbis) in North America

The lesser kudu (Tragelaphus imberbis) has been kept in North American zoological parks since 1930 but has never been a common species in collections. In 1987 this population totaled 28 animals: 15 males and 13 females. A pedigree evaluation in 1987 of the existing population indicated that eight effective founders and one potential founder were represented in the North American herd. Three new potential founders from European captive populations were added to the population in 1987 to increase the number of existing founder lines to 12 animals. As this species is not endangered or threatened in its native habitat, it is not a high priority to qualify for designation as an SSP species. Because of this, the institutions holding lesser kudu in North America decided to join informally and draft a breeding program to better manage this small captive population. This program was designed to minimize inbreeding and equalize genetic representation of founder animals to maximize genetic diversity. It requires a shift in management philosophy to establish stable groups of breeding females at participating institutions while rotating appropriate breeder males through these herds in a controlled manner to ensure minimization of inbreeding and maximization of genetic diversity. It is hoped that this program can serve as a model for the management of other small captive populations of non-SSP species.     

Pollination biology of two species ofKielmeyera (Guttiferae) from Brazilian cerrado vegetation

The pollination biology and breeding systems ofKielmeyera coriacea andK. speciosa, two sympatric woody species common in the cerrado vegetation of C. Brazil, were studied. Both species have similar nectarless, polystemonous Papaver-type flowers which are visited by a similar spectrum of insects, though they bloom in different seasons and are thus phenologically isolated. Large carpenter bees seem to be the most important pollinators and these and other bees effect buzz pollen retrieval despite the fact that anthers are not poricidal. Both species ofKielmeyera possess strong xenogamous breeding systems. The presence of staminate flowers and andromonoecy inK. coriacea, as well as the longevity ofK. speciosa flowers are discussed as alternative strategies to improve pollination success and reproductive efficacy.     

Chromosomal distinction between the red-faced and black-faced black spider monkeys (Ateles paniscus paniscus and A. p. chamek)

The two subspecies of the black spider monkey, Ateles paniscus paniscus and A. p. chamek, can be distinguished by their chromosome number, 2n = 32 in the former and 2n = 34 in the latter. This difference most probably is the result of a tandem fusion between chromosomes 4 and 13 of the original Ateles karyotype (2n = 34) to form a unique metacentric chromosome in A. p. paniscus. Further differences between the subspecies concern the presence of additional interstial or terminal C-bands in chromosomes 3, 5, and 12 of A. p. paniscus. A third difference is that chromosome 12 is metacentric in A. p. paniscus but is submetacentric in A. p. chamek. A. p. chamek shows dimorphisms caused by pericentric inversions in pairs 1, 5, 6, and 7 as well as in the Y chromosome. Since the dimorphisms in pairs 5 and 7 are only found in homozygous condition, they may indicate the existence of geographic variation within this subspecies. Differences in external characteristics possibly reflect these chromosomal difference. The necessity to lend A. p. paniscus full specific status should be considered, since karyologically this is the most distinct one of all forms of Ateles. In captive breeding A. p. paniscus should evidently be treated as a separate population, as hybridization with A. p. chamek may result in offspring with reduced fertility. The intra-subspecific karyological variation in A. p. chamek and its possible consequences for taxonomy and captive breeding require further investigation.     

Breeding Systems in American and Asian Trillium Species by Means of Chromosome Analyses

Abstract Species of Trillium have a disjunct distribution occurring in both North America and eastern Asia. In North America all 36 species are diploid. The 11 species of eastern Asia, however, include only a single diploid with all the other species being polyploids. Why do different patterns of speciation develop in North America and in eastern Asia? The breeding systems of populations in the North American T. erectum, T. grandiflorum and T. ovatum , and in Asian T. kamtschaticum were investigated by estimating the inbreeding coefficient from cold-induced banding patterns which reveal homozygotes and heterozygotes. From the analyses of the inbreeding coefficients, T. erectum, T. grandiflorum and the Pacific coastal species, T. ovatum are predominantly inbreeding species. T. ovatum populations from the Rocky Mountain region are outbreeders. However the Japanese species, T. kamtschaticum has a mixture of outbreeding and inbreeding among populations. The development of polyploid systems in Asia is possibly the result of the diversity of the breeding systems among the populations. The shift from outbreeding to inbreeding appears to be an important key step in the occurrence of poliploids by hybridization between the different species.     

Growth and reproduction of the mosquitofish,Gambusia affinis,in relation to temperature and ration level: consequences for life history

The allocation of energy to growth and reproduction, in relation to temperature and food availability, was investigated in laboratory experiments with the mosquitofish,Gambusia affinis. At constant temperature of 20, 25 and 30°C and ad libitum feeding, specific growth rates increased with increasing temperature at 1.7, 3.1 and 3.4% dry mass day⁻¹, respectively. Growth rates in a cycling temperature regime (20–30°C, ) were faster than in a 25°C constant temperature. As temperature increased from 20 to 30°C, mean age at first reproduction decreased from 191 to 56 days and brood size and mass of offspring increased significantly. Interbrood interval was also temperature dependent; estimates at 25 and 30°C for females >1000 mg were 22.6 and 18.6 days, respectively. Interbrood interval could not be calculated at 20°C. Although fitness was highest at 30°C, females at 25°C invested a greater proportion of surplus energy (growth and reproduction) to reproduction (38%) than at 20 (17%) or 30°C (36%) during the 32-week study. Fish at cooler temperatures began reproduction at a smaller size. Where rations were controlled at low, medium, and ad libitum levels, somatic and gonadal growth increased with increasing temperatures and food availability. The proportion of energy invested in reproduction was highest at 25°C for each comparable ration level. Calculated energy budgets indicated that over the 10-week study, 17–22% of the food energy was invested in growth, 0–7% in reproduction, and 75–83% in respiration and excretory losses, depending on feeding and temperature conditions.     

Occurrence of rye (Secale cereale) 350-family DNA sequences inAgropyron and otherTriticeae

Evidence is presented that in the R and P genomes (Secale cereale andAgropyron cristatum, respectively) of theTriticeae there exist closely related 350-family DNA sequences in the terminal heterochromatin. This observation is compared to the relationships between these two genomes derived from a comparison of theNor and5 S DNA loci as well as the available data on morphological characters, chromosome pairing, and isozyme studies. It is concluded that the R and P genomes are not closely related and that the common presence of very similar 350-family DNA sequences reflects the parallel amplification of this family of DNA sequences.     

The cytogeographical distribution pattern ofAllium (Alliaceae) in the Greek Peninsula and Islands

Greece is considered as a secondary centre of evolution for the genusAllium since it possesses about 50% of the species known from the whole Flora Europaea area. In the present investigation 44 GreekAllium spp. have been studied and new chromosome counts are reported from 40 populations and 17 species. The distribution of the different cytotypes (x = 7, x = 8, x = 11 and 2n = 2x, 3x, 4x, 5x, 6x, 7x) in Greece is discussed. From the four phytogeographical subdivisions recognized, South continental Greece shows the greatest species and karyotype diversity. This phenomenon is probably due to the geographical position and to the geological history of this area which has received species and populations from different directions. Subsequently, hybridization apparently has been of evolutionary importance.The genusAllium in Greece I.     

Decreased fertility in related females heterozygous for the 1/29 chromosome translocation

Eighteen heifers and 120 cows which were descendants of a presumed 1/29 carrier Simmental bull were karotyped. Nine heifers (50%) and 48 cows (40%) were found to be heterozygous for the 1/29 translocation (59, XX, t(1q;29q)). The other animals were chromosomally normal (i.e., 60, XX) or not karotyped. The 48 1/29 cows were compared with 72 chromosomally normal cows with regards to days to first conception, calving interval, percentage of calves conceived, percentage of calves weaned and production efficiency (% calved conceived × % calved weaned). Nine carrier heifers were compared to the nine noncarrier heifers as to pregnancy status. Carrier, noncarrier and nonkarotyped relatives were compared to each other and to contemporary females with regard to pregnancy status at their initial exposure to males. The percentage of calves conceived (calving efficiency) in the 72 noncarrier and the 48 females heterozygous for the 1/29 translocation were 81.5 and 74.8%, respectively (P<0.07). Although days to first conception was longer and percentage of calves weaned and production efficiency were lower in the female heterozygous for the 1/29 translocation, the differences were not statistically different (P>0.10) from the noncarriers. Pregnancy rate was 44.4 and 66.7% (P>0.10) for nine carrier and nine noncarrier heifers, respectively. The pregnancy rate of carrier (65.4%), noncarrier (73.2%) and nonkarotyped (77.8%) relatives of this sire at their mating as yearlings, did not differ (P>0.10). The pregnancy rate as yearlings of carrier females (65.4%) and contemporary heifers (79.8%) did differ (P<0.05). Comparing the pregnancy rate as yearlings of all descendants (72.0%) of the Simmental sire to contemporary heifers (79.8%), a significant decrease (P<0.05) was found indicating that fertility of this sire may have been lower than other sires or that other factors beside the translocation affected fertility.     

五种恙螨染色体核型的研究

恙螨染色体的研究迄今仅Shirai等(1984)简要地报道了三种纤恙螨的染色体核型。本实验采用压片法和改良空气干燥法,研究观察五种恙螨有丝分裂染色体核型。初静止化蛹1—3天的成蛹阶段是制作恙螨有丝分裂染色体标本的最佳虫期。微红纤恙螨,地里纤恙螨和巨螫齿恙螨染色体数目为2n=14;苍白纤恙螨和小板纤恙螨为2n=16。染色体呈大小不等的小棒状,单着丝粒,但多不清晰,仅可见着丝点区浅染。部分核型出现染色体异型现象。核型性别未明,性别决定机制不清。