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The genetic stability and maintenance of Raphanus sativus-Brassica rapa monosomic chromosome addition lines (a-h-types MALs, 2n = 19, BC[SUB2]), developed by backcrossing the synthesized amphidiploid Raphanobrassica (Raphanus sativus × Brassica rapa, 2n = 38, RRAA) with R. sativus cv. 'Shogoin' (2n = 18, RR), was investigated. Transmission of the added alien chromosome through selected smaller seeds (SSS) and the inheritance of morphological traits and random amplified polymorphic DNA (RAPD)-specific markers together with meiotic chromosome configuration and seed fertility were also investigated for three successive generations (BC[SUB3] to BC[SUB5]). The distinctive traits and the RAPD-specific markers of the eight types of MAL were substantially inherited and stably maintained throughout three generations, although a few variant plants (2n = 18) resembling MALs (2n = 19) and hyperploidal plants (2n = 26 and 2n = 37) were generated in the earlier generations of BC[SUB3] and BC[SUB4] in comparison with BC[SUB5]. The average transmission rates for three generations ranged from 26% for both the b-type and the d-type to 44% for the e-type through SSS. On the other hand, the transmission rates through randomly selected seeds (RSS) were lower, ranging from 6.5% for the f-type to 23.5% for the b-type. In meiosis, more than 90% of PMCs showed the 9II + 1I pairing configuration at metaphase I throughout three generations. For seed fertility, when backcrossed with the radish cv. 'Shogoin', the values were approximately 180% to 500% with the mode around 300% with the seed harvested from a pod increasing with the advancing generations. Genetic recombination between the radish chromosomes and the added chromosome is probably rare, suggesting that the added chromosome is mostly maintained unaltered in the background of the radish genome. [ABSTRACT FROM AUTHOR]

Intergeneric F[SUB1] hybrids between Raphanus sativus (2n = 18, RR) and Moricandia arvensis (2n = 28, MaMa) have been produced through ovary culture followed by embryo culture, when M. arvensis was used as a pistillate parent. Six BC[SUB1] plants were also obtained through ovary culture followed by embryo culture in the backcross of an amphidiploid F[SUB1] hybrid with R. sativus cv. 'Pink ball'. Two BC[SUB1] plants were sesquidiploids (2n 32, MaRR), and the other BC[SUB1] plants were hyperploid with 2n = 55, having MaMaRRR genomes. BC[SUB2] seeds were obtained by conventional pollination in the successive backcross of two sesquidiploid BC[SUB1] plants with R. sativus cv. 'Pink ball'. Their seed set percentages were 12.7% and 17.0%, respectively. These novel hybrid plants and derived progenies may be valuable materials for the genetic investigation and breeding of Brassiceae, including R. sativus. [ABSTRACT FROM AUTHOR]

For the development of a new cytoplasmic male sterility (CMS) system in Brassica rapa (2n = 20, AA), intergeneric hybridization was performed in Eruca sativa (2n = 22, EE) × B. rapa. The original amphihaploid F[sub 1] plant (2n = 21, EA) generated via embryo rescue produced a sesquidiploid F[sub 2] plant (2n = 31, EAA), from which the alloplasmic F[sub 3] plants were generated. In F[sub 3], some progenies with malformed anthers were maintained as male-sterile lines up to the F[sub 6] generation. In the F[sub 7] and F[sub 8] generations, the alloplasmic male-sterile plants were bred by backcrossing to several B. rapa genotypes and were then classified into the three distinctive types: petaloid, antherless and brown anther, in addition to three intermediate types between them. By southern blot analysis, each plant of the petaloid and antherless types was shown to carry the cytoplasm genome of E. sativa. These male-sterile plants produced as many viable seeds as the corresponding male-fertile plants, although their nectary gland development was minimal. Consequently, CMS lines of the petaloid and antherless types with enhanced seed fertility and nectary gland development could provide promising plant materials for F[sub 1] seed production in B. rapa. [ABSTRACT FROM AUTHOR]

Intergeneric hybridization was performed between Brassica rapa and Diplotaxis tenuifolia following embryo rescue. Twenty-three F1 hybrid plants were developed from the cross B. rapa × D. tenuifolia and confirmed to be amphihaploids with 21 chromosomes in mitosis. Chromosome doubling of F1 hybrids by colchicine treatment resulted into five amphidiploid plants which exhibited (20–21)II + (0–2)I at metaphase I (MI) of pollen mother cells. Sib-crossing and/or open-pollination among amphidiploid plants for more than four generations resulted in the development of an ADt-06 line with reproductive systems capable of maintaining an amphidiploid line. The ADt-06 line was intermediate in some morphological traits between two parental species, and was characterized by a slightly pungent taste as a physiological trait. Analyses for genomic DNA confirmed that this line was a hybrid between two species. This new amphidiploid ADt-06 line could be a useful genetic resource for the breeding of new leafy salad vegetables. [ABSTRACT FROM AUTHOR]

The thiosulfate reductase gene (phsABC) from Salmonella enterica serovar Typhimurium was expressed in Escherichia coli to overproduce hydrogen sulfide from thiosulfate for heavy metal removal (or precipitation). A 5.1-kb DNA fragment containing phsABC was inserted into the pMB1-based, high-copy, isopropyl-beta-D-thiogalactopyranoside-inducible expression vector pTrc99A and the RK2-based, medium-copy, m-toluate-inducible expression vector pJB866, resulting in plasmids pSB74 and pSB77. A 3. 7-kb DNA fragment, excluding putative promoter and regulatory regions, was inserted into the same vectors, making plasmids pSB103 and pSB107. E. coli DH5alpha strains harboring the phsABC constructs showed higher thiosulfate reductase activity and produced significantly more sulfide than the control strains under both aerobic and anaerobic conditions. Among the four phsABC constructs, E. coli DH5alpha (pSB74) produced thiosulfate reductase at the highest level and removed the most cadmium from solution under anaerobic conditions: 98% of all concentrations up to 150 microM and 91% of 200 microM. In contrast, a negative control did not produce any measurable sulfide and removed very little cadmium from solution. Energy-dispersive X-ray spectroscopy revealed that the metal removed from solution precipitated as a complex of cadmium and sulfur, most likely cadmium sulfide.

The lung and stomach are very unusual sites for teratoma. The histologic findings of intrapulmonary and gastric teratomas are not different from those arising in usual sites, such as the ovary or testis. However, preoperative diagnosis is sometimes difficult to make partly because of unusual location. We report here two cases of teratoma, one intrapulmonary teratoma and the other gastric. The intrapulmonary teratoma in our study had an endobronchial tumor growth, which rules out mediastinal teratoma. Meanwhile gastric teratomas usually present as a submucosal tumor and most cases are reported in infancy and childhood. Gastric teratoma in this study occurred in a 27-year-old man. To the best of our knowledge, this case of intrapulmonary teratoma is the eighth and the gastric teratoma is the first to be reported in Korea.