Ikuo Miyajima

Colchicine induced tetraploids in yellow-flowered cyclamens and their characteristics

Abstract The possibility of obtaining tetraploids from diploid yellow-flowered cyclamen ‘Kage Yellow’ through colchicine treatment and the effects of polyploidization on the characteristics of yellow-flowered cyclamen were investigated. A 4-day treatment of tuber segments with 100 mg l −1 colchicine in vitro yielded two tetraploid plants. The petals of the tetraploids were larger and had a greater ability to accumulate chalcone than those of their diploid relatives. Polyploidization may therefore represent a useful method for the commercial breeding of deeper yellow-flowered cyclamen.

Appearance of albino seedlings and ptDNA inheritance in interspecific hybrids of azalea

PCR-RFLP analysis was conducted to clarify the relationship between the leaf color of progenies and their ptDNA inheritance in interspecific three-way crosses, (Rhododendron kiusianum × R. eriocarpum) × R. japonicum f. flavum. All albino progenies contained maternal ptDNA, whereas green and pale-green progenies contained paternal ptDNA. Sectorial chimeric progenies, of which the leaf and shoot color was turned from green to albino during the culture, contained both maternal and paternal ptDNA in green segments and maternal ptDNA in albino segments. These results suggest that albino progenies are caused by the incompatibility between plastome from F1 hybrids of R. kiusianum × R. eriocarpum and nuclear genome from R. japonicum f. flavum.

Somatic embryogenesis ofCyclamen persicum Mill. 'Anneke' from aseptic seedlings.

SummaryInCyclamen persicum ‘Anneke’, explants from the various vegetative organs of aseptic seedling formed embryoids. The optimal responses were recorded in Murashige and Skoog (MS) medium enriched with 5.0µM 2,4-dichlorophenoxyacetic acid (2,4-D), 0.5µM kinetin and 3–6% sucrose. Embryogenesis was enhanced at higher temperature of 25–30°C. On the other hand, light inhibited embryogenesis. Histological and morphological studies confirmed that the embryoids were indeed somatic embryos.

Effectiveness of three-way crossing for the breeding of yellow-flowered evergreen azalea

For the purpose of obtaining yellow-flowered evergreen azaleas, single and three-way interspecific crosses between evergreen azaleas and Rhododendron japonicum f. flavum were compared. In single cross, although many seeds were obtained from R. eriocarpum × R. japonicum f. flavum, the seedlings from immature ovule were albino or pale-green plants. They were withered away at acclimation. In R. kiusianum × R. japonicum f. flavum, green seedlings were observed, but number of ovules contained in one capsule was very small. In three-way cross, (R. kiusianum × R. eriocarpum) × R. japonicum f. flavum, many viable seeds were contained in one capsule, and about 15% of the seedlings were green leaf colored. These results suggest that three-way cross is one of the useful breeding methods for creating the new yellow-flowered evergreen azalea. Isozyme analysis revealed that most of seedlings were zygotic origin without distinction of their leaf colors, but some green seedlings indicated the same genotypes as the seed parents. Therefore, it is important to confirm hybridity of the seedlings by isozyme technique.

Inheritance of yellow-flowered characteristic and yellow pigments in diploid cyclamen (Cyclamen persicum Mill.) cultivars

Abstract The mode of inheritance of the yellow-flowered phenotype of yellow-flowered cyclamen was investigated. All F 1 progenies obtained by reciprocal crosses between yellow- and white-flowered cultivars were white-flowered and did not contain chalcone, the main pigment of yellow-flowered cyclamen. The segregation ratio of flower colors in most of F 2 and BC 1 progenies fitted the expected Mendelian ratio, showing that the yellow-flowered phenotype was controlled by a single recessive gene. The petals of all yellow-flowered plants in F 2 and BC 1 progenies contained chalcone. It is suggested that a single recessive gene causes the lack or defectiveness of chalcone-flavanone isomerase and determines the yellow-flowered phenotype.

Flower colours and pigments in hybrid tuberose (Polianthes)

Abstract The flower pigment constitutions of nine hybrids with pink, reddish purple, purple, orange and yellow flowers obtained from the crossings and back-crossings using Polianthes tuberosa ‘Single’ and ‘Double’ and Polianthes howardii were analysed. Among the parents and hybrids, two white flowered cultivars of P. tuberosa had neither carotenoids nor anthocyanins, one hybrid had only carotenoids, four hybrids had only anthocyanins and an additional other four hybrids along with P. howardii had both carotenoids and anthocyanins in their petals. The main anthocyanidin in the petals of anthocyanin containing flowers is cyanidin with which some hybrids also contained delphinidin. Inducing of the anthocyanins and carotenoids from P. howardii into P. tuberosa can contribute to the extension of the diversity of flower colours in further tuberose breeding.

Flower colors and pigments in hybrids with Camellia chrysantha

Abstract The yellow pigment components of the interspecific hybrids of ‘Suzanne Withers’ ( C. reticulata × C. saluenensis , seed parent) × C. chrysantha (pollen parent), ‘Lasca Beauty’ ( C. reticulata × C. japonica , seed parent) × C. chrysantha (pollen parent) and the parents were analyzed. C. chrysantha contains three major flavonols and some carotenoids, ‘Suzanne Withers’ has two major flavonols, while ‘Lasca Beauty’ has no yellow pigment detected. The yellow pigment genes from both parents were expressed in hybrids of ‘Suzanne Withers’ × C. chrysanthan because yellow pigments characteristic of both parents were detected in the petals of the hybrids. Quercetin-7-glucoside, which is the most important yellow pigment in C. chrysantha , was found in small amounts in progenies. In hybrids of ‘Lasca Beauty’ × C. chrysantha the yellow pigments observed were those from C. chrysantha ; however, quercetin-7-glucoside was not found in them, only the other two flavonols and carotenoids were detected.

Introgressive hybridization between Rhododendron kiusianum and R. kaempferi (Ericaceae) in Kyushu, Japan based on chloroplast DNA markers

Wild evergreen azalea populations of Rhododendron kiusianum and R. kaempferi ( Ericaceae ) were analysed using a chloroplast DNA (cpDNA) PCR-RFLP marker that was used to detect introgressive hybridization in our previous study of the Kirishima Mts populations. The populations of the intermediate region in the Unzen Mts, which show phenotypic variation, were demonstrated to result from interspecific hybridization between Rhododendron kiusianum and R. kaempferi , possessing cpDNA from either R. kiusianum (1030/420 bp) or R. kaempferi (950/420/80 bp). Most individuals of Rhododendron kiusianum in the Kujyu Mts, the Aso Mts and the surrounding mountains exhibited the PCR-RFLP pattern of R. kaempferi . These results from the Kujyu Mts and the Aso Mts indicate that natural hybridization and cytoplasmic introgression from Rhododendron kaempferi to R. kiusianum have occurred in the relatively distant past. In the case of Mt Yufudake and Mt Haneyama, the Rhododendron kiusianum population retains the effects of natural hybridization with R. kaempferi in the cpDNA as well as in the variation in flower characteristics. All individuals of Rhododendron kiusianum on Mt Onogaradake in the Takakuma Mts exhibit R. kiusianum cpDNA (1030/420 bp), in spite of variation in flower colour.

Identification of Plant Stains Using High Performance Liquid Chromatography

A study was designed to identify stains derived from plant pigments. Using high performance liquid chromatography (HPLC), 13 species of common weeds were examined, and 12 flavonoids were detected from as low as 100 to 200 μg of dried leaves and from their stains. Identification of plant species could be made, based on the various chromatographic patterns of the flavonoids with different retention indices, using rutin and rhamnetin as the reference standards. A brief practical case of application is described.

Study on Backfilling of Soil for Revegetation at the Rehabilitation Area in Indonesian Coal Mine

Mining operation of open cut mines gives serious impacts on surrounding environment such as disturbance of the tropical rainforest, the pollution of surface and/or ground water, subsidence and erosion. Rehabilitation is one of the important and considerable topics for an environment protection under such situations. Adequate rehabilitation program will solve these environmental issues and recover the ecosystem. The basic concept of rehabilitation in open cut mines is the creation of a stable and self-sustaining land surface in post mine surface involved the creation of conditions suitable for the establishment and permanent development of a dense cover of vegetation. In usual, a lot of open cut mine keep the topsoil individually in the natural forest during soil stripping process and spread the topsoil to rehabilitation area for success of revegetation. However, there are some considerable points for dealing with topsoil in situ such as the soil properties and severe compaction by heavy equipment. Therefore, the proper topsoil management has to be considered for establishment of vegetation in post mine surface.