Pollen and Resource Limitation in Veratrum nigrum L. （Liliaceae）, an Andromonoecious Herb

Pollen limitation and resource limitation were invoked to account for the pattern that flowering plants produce more flowers and ovules than fruits and seeds. This study aimed to determine their relative importance in Veratrum nigrum, a self-compatible, perennial, andromonoecious herb. In order to determine whether female production was limited by pollen grains on stigmas or by available resources, we performed supplemental hand pollination in three populations, male-flower-bud removal in three other populations, and emasculation of hermaphroditic flowers in still another population, resulting in a total of seven populations experimentally manipulated. Across the three populations, supplemental hand pollination did not significantly increase fruit set, seed number per fruit, and total seed production per individual, nor did emasculation of hermaphroditic flowers. Taken together, our results suggest that pollen grains deposited on stigmas were abundant enough to fertilize all the ovules. Male-flower-bud removal significantly increased the mean size of hermaphroditic flowers in all three populations. Female reproductive success was increased in one population, but not in the other two populations possibly due to heavy flower/seed predation. We concluded that the female reproductive success of V. nigrum was not limited by pollen grains but by available resources, which is consistent with Bateman＇s principle. Furthermore, the female reproduction increase of male-flower-bud removal individuals might suggest a trade-off between male and female sexual functions.     

Carlina×bakariensis E.Mayer,hybr. nov. (=C. fiumensis Simk.×C. corymbosa L.)

Zusammenfassung Die chorologischen und morphologisch-taxonomischen Verhältnisse vonCarlina frigidaBoiss. etHeldr.,C. fiumensisSimk.,C. graecaHeldr. etSart, undC. corymbosa L. im adriatischen Küstengebiet von Jugoslawien werden näher besprochen.Aus dem Gebiet des Quarnero wird der erste sichere Bastard innerhalb der GattungCarlina L.,C.×bakariensis (=C. fiumensisSime.×C. corymbosa L.), beschrieben.     

Identification of QTLs with Additive,Epistatic, and QTL × Seed Maturity Interaction Effects for Seed Vigor in Rice

Seed maturity is a critical process of seed vigor establishment. In this study, one rice population of recombinant inbred lines (RILs) was used to determine the genetic characteristics of seed vigor, including the germination potential (GP), germination rate (GR), germination index (GI), and time for 50 % of germination (T₅₀), at 4, 5, and 6 weeks after heading in 2 years. Significant differences of seed vigor were observed among two parents and RIL population; the heritability of four traits was more than 90 % at three maturity stages. A total of 19 additive and 2 epistatic quantitative trait loci (QTL) for seed vigor were identified using QTL Cartographer and QTLNetwork program, respectively, in 2012, while 16 simple sequence repeat (SSR) markers associated with seed vigor were detected using bulked segregant analysis (BSA) in 2013. The phenotypic variation explained by each additive, epistatic QTL, and QTL × seed maturity interaction ranged from 9.19 to 22.94 %, 7.23 to 7.75 %, and 0.05 to 0.63 %, respectively. Ten additive QTLs were stably expressed in 2 years which might play important roles in establishment of seed vigor in different environments. By comparing chromosomal positions of ten stably expressed additive QTLs with those previously identified, they might be true QTLs for seed vigor; the regions of QTLs for seed vigor are likely to coincide with QTLs for seed dormancy, seed reserve mobilization, low-temperature germinability, and seedling growth. Using four selected RILs, three cross-combinations were predicted to improve seed vigor; 9 to 10 elite alleles could be pyramided by each combination. The selected RILs and the identified QTLs might be applicable for the improvement of seed vigor by marker-assisted selection (MAS) in rice.     

Karyotype and genomic in situ hybridization pattern in ×Brassicoraphanus, an intergeneric hybrid between Brassica campestris ssp. pekinensis and Raphanus sativus

The karyotype and genomic in situ hybridization (GISH) of an intergeneric hybrid Baemoochae, ×Brassicoraphanus, which originated from hybridization between Chinese cabbage, Brassica campestris (synonym, rapa) ssp. pekinensis, and radish, Raphanus sativus, were analyzed to determine its chromosome complement. In the karyotype analysis, B. campestris was verified to have 2n = 20 chromosomes, including a particular pair of the subtelomeric chromosomes with the nucleolar organizer; R. sativus to have 2n = 18 chromosomes, including a particular pair of the submetacentric chromosomes with the secondary constriction of nucleolar organizer; and ×Brassicoraphanus to have 2n = 38 chromosomes, including both the subtelomeric chromosomes of Brassica and the secondary constriction chromosome pair of Raphanus. These findings indicate that ×Brassicoraphanus is a polyploid between Brassica and Raphanus. In the GISH analysis using chromosomes of B. campestris and R. sativus as the probe and blocking DNA, respectively, only 20 chromosomes of Brassica had hybridization signals. This result reveals that ×Brassicoraphanus is an intergeneric hybrid consisting of the complete genomes of both Brassica and Raphanus. However, the nucleolar organizers of Brassica and Raphanus were not identified because the hybridization signals appeared to be centering mainly around the centromere, becoming weak at the edges.     

Isolation and Identification of a Novel β-Carboline Derivative in Salted Radish Roots,Raphanus sativus L.

The methanol extract of salted radish roots contains several precursors of yellow pigment. The main compound was isolated by the use of Toyopearl HW-40S column chromatography, and its structure was determined to be 1-(2′-pyrrolidinethion-3′-yl)-1,2,3,4-tetrahydro-β-carboline-3-carboxylic acid on the basis of an elemental analysis, and IR, UV, FAB-MS and NMR spectroscopy. This compound is presumed to have been the condensation product from the degradation of 4-methylthio-3-butenyl isothiocyanate and l-tryptophan. This carboline compound is considered to play an important role in the formation of the yellow pigment in salted radish roots.     

Effect of tropospheric ozone on morphological characteristics of Nicotiana tabacum L., Phaseolus vulgaris L. and Petunia×Hybrida L. in ambient air conditions

The cumulative ozone effect on morphological parameters (visible leaf injury, plant height and leaf growth, number of bean pods, petunia flowers and stalks) was examined in this study. Well-known ozonesensitive (Bel W3) and ozone-resistant (Bel B) tobacco cultivars as well as bean cv. Nerina and petunia cv. White cascade, both recognized as ozone sensitive, were used in the experiment. Investigations were carried out at two exposure sites varying in tropospheric ozone levels. Ozone negatively affected the leaf growth of both tobacco cultivars and bean. A negative relation was also found for ozone concentration and tobacco plant height. Number of petunia flowers and stalks and bean pods was positively correlated with ozone concentration. This could have been connected with earlier plant maturation due to faster generative development of plants in ozone-stress conditions.     

RAPD Fingerprinting of Common Bream Abramis brama L., Roach Rutilus rutilus L., and Their F1 Hybrids (A. brama × R. rutilus and R. rutilus × A. brama)

The polymerase chain reaction with arbitrary primers (RAPD–PCR) was used to study and to evaluate the genetic variation in the hybrid progeny of two Cyprinidae species, common bream Abramis brama L. and roach Rutilus rutilusL. Genetic polymorphism was studied in 20 fishes (young of the current year) obtained in four individual crosses: R. rutilus × R. rutilus (RR), A. brama × A. brama (AA), R. rutilus × A. brama (RA), and A. brama × R. rutilus (AR). Amplification spectra obtained with eight primers contained 288 fragments, 97.6% of which proved to be polymorphic. The proportion of polymorphic fragments was 75.0% in the RR progeny, 58.1% in the AA progeny, 84.9% in the AR progeny, and 77.8% in the RA progeny. Classification analysis in the space of principal components was performed with the first four components, which together accounted for 64% of the total variance of the character under study. The individual contributions of components I, II, III, and IV were 26.8, 16.8, 11.5, and 8.9%, respectively. Fishes of the two pure species and the hybrid progeny (direct and reverse hybrids together) were clearly differentiated in the space of principal components I and II. The best differentiation of the four samples (RR, AA, RA, and AR) was observed in the space of principal components II and IV. Possible causes of high genetic variation in interspecific hybrids are discussed.     

Germplasm conservation of the tropical forest trees,Cedrela odorata L.,Guazuma crinita Mart., andJacaranda mimosaefolia D. Don., by shoot tip encapsulation in calcium-alginate and storage at 12–25°C

Germplasm conservation of the tropical forest trees,Cedrela odorata L.,Guazuma crinita Mart., andJacaranda mimosaefolia D. Don., at above-freezing temperatures following alginate-bead encapsulation was attempted. Shoot tips excised from in vitro plantlets were encapsulated in calcium-alginate beads and stored on different substrates at 12, 20, and 25 °C. Percent viability when encapsulated shoot tips were stored on substrate containing only water solidified with 1% (wt/vol) agar was 80% after 12 months at 12°C forC. odorata, 90% after 12 months at 25°C forG. crinita, and 70% after 6 months at 20°C forJ. mimosaefolia.Abbreviations BAP 6-Benzylaminopurine - KIN 6-Furfurylaminopurine     

Polycomb-group （Pc-G） Proteins Control Seed Development in Arabidopsis thaliana L.

Polycomb-group （Pc-G） proteins repress their target gene expression by assemble complexes in Drosophila and mammals. Three groups of Pc-G genes, controlling seed development, flower development and vernalization response, have been identified in Arabidopsis （Arabidopsis thaliana L.）. MEDEA （MEA）, FERTILIZATION INDEPENDENT SEED2 （FIS2）, and FERTILIZATION INDEPENDENT ENDOSPERM （FIE） are Pc-G genes in Arabidopsis. Their functions in seed development have been extensively explored. The advanced findings of molecular mechanism on how MEA, FIS2 and FIE control seed development in Arabidopsis are reviewed in this paper.     

Effects of drought stress on the evergreen Quercus ilex L., the deciduous Q. robur L. and their hybrid Q. × turneri Willd.

Five-year-old trees of deciduous Quercus robur L., evergreen Q. ilex L., and their semideciduous hybrid, Q. × turneri Willd. (var. pseudoturneri), growing in pots, were subjected to drought stress by withholding water for 18–22 days, until leaf water potentials decreased below ?2 MPa. Gas-exchange rates, oxygen evolution, and modulated chlorophyll (Chl) fluorescence measurements revealed that by strong stomata closure and declining photosynthetic capacity down to approximately 50%, all three taxa responded with strongly reduced photosynthesis rates. In Q. robur, photochemical quenching of the drought-stressed plants was much lower than in nonstressed controls. Dissection of the occurring events in the photosynthetic electron transport chain by fast Chl fluorescence induction analysis with the JIP-test were discussed.     

Heavy metals dynamics in seaweeds and seagrasses in Bahía Magdalena,B.C.S., México

The process of metal bioaccumulation in marine food chains is poorly understood because very little data is available on metal concentration at different trophic levels and their temporal or spatial variation. Because of that, we were interested to (1) determine the concentration range of heavy metals in seaweed and seagrasses species in Magdalena Bay; (2) describe the spatial and temporal variation of heavy metal concentrations in the seaweeds and seagrasses. Seasonal collections were done at Estero Banderitas in November 2004, February, and April 2005 wherein we divided the estuary into three major areas (upper, middle, and lower), and within each area, two sites were selected. Our results showed that iron, copper, and magnesium were the most significant metals found in seagrasses, red, and green algae. We found significant more variation in temporal heavy metal concentrations in relation to the maximum abundance in the samples and spatial variation in relation to the studied taxa suggesting that hervibores have a differential intake of the metals. Also, our results suggest that heavy metals might be incorporated regularly in the diet of many herbivorous animals with severe consequences to their health. Management strategies for these species should consider monitoring the levels of metals.