The flower trait of a long-lasting corolla with a temporal color change, called "misome-sho", is found in several evergreen azalea cultivars of Japan. For the purpose of applying the "misome-sho" trait for breeding, we investigated the floral mor phology and inheritance pattern using these cultivars and their crossed progenies. All five "misome-sho" cultivars have smaller corolla and smaller epidermal cells on the abaxial surface of the corolla compared with wild type flowers. Also "misome-sho" cultivars have a number of stomata and trichomes on the abaxial surface of the corolla. This may lead to sepaloid features occurring at the corolla. All F 1 progenies between wild type flowers and "misome-sho" cultivars showed wild type flowers. On the other hand, all F 1 progenies between "misome-sho" cultivars showed "misome-sho" trait flowers. Wild type flowers and "misome-sho" trait flowers were segregated at a 3 : 1 ratio in the crossed progenies between F 1 hybrids of wild type flowers and "misome-sho" cultivars. These results indicate that the "misome-sho" trait is controlled by a single recessive gene and a similar morphological mutation is caused by a common gene mutation in "misome-sho" cultivars. To increase the size of the small corolla of "misomesho" cultivars, the effectiveness of using large-flower cultivars as cross parents was indicated in a breeding program.

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For the purposes of utilizating genetic resources and conserving endangered endemic Japanese species, interspecific hybrids between Veronica ornata Monjuschko (Plantaginaceae) and V. ogurae (T. Yamaz.) Albach in Shimane Prefecture were created. In the reciprocal crossings, hybrid seeds were obtained from only the cross involving V. ornata as the seed parent and V. ogurae as the pollen parent. The expected number of obtained seeds on interspecific crossing was 0.5 per flower. The hybridity of the obtained seedlings was confirmed as the original bands were inherited from both parents in the SRAP method. In the characterization of the parents and their 92 hybrids in the flowering season, the leaf size and amount of pubescence in the stems and leaves of the hybrids were intermediate between the parents, and the spike length and flowering period of the hybrids were longer than those of the parents. The inheritance of these ornamental characteristics was supported by the results of principal component analysis. The results of this study suggest the possibility of being able to develop superior cultivars by crossing and selection focusing on ornamentally important characteristics.

To develop potted flower production of Veronica ornata (Plantaginaceae), which is a useful genetic resource endemic to Japan, the effects of pinching season and node order on flowering time and quality were investigated. As the pinching season become later, the flowering become later in the experiment using the potted flower 'NG-1'. Also, as the pinching season become later, the accumulation of heat units until flowering was decreased. Regarding the potted flower quality at harvest, as the pinching season become later, the node number to flowering and the shoot length were decreased. In the case of a higher pinching position, flowering became earlier, the accumulative temperature to flowering was decreased, and the node number to flowering and shoot length were decreased. Flowering shoots were increased by pinching in all seasons and the node order in this experiment. Blind shoots were also increased by pinching at the end of June or with a low node order. These results indicate that the flowering time and quality can be controlled by means of pinching timing and the node order on potted flower production of V. ornata. Shipping of the potted flowers may be possible in early September for Respect for the Aged Day by means of pinching above 2 or 3 nodes from the base at the end of May.

There is a long-lasting flower trait with a temporal color change, known as "misome-shō", in Japanese evergreen azalea. This trait has been found in several wild Japanese evergreen azalea species, such as Rhododendron kaempferi 'Nikkō-misome', R. macrosepalum 'Kochō-zoroi', R. indicum 'Chōjyu-hō', and R. × hannoense 'Amagi-beni-chōjyu'. The corollas of long-lasting flower cultivars undergo a conversion of normal corollas to sepaloid corollas due to loss of function of the MADS-box B class gene, APETALA3 (AP3) homolog. Also, the long-lasting flower trait was shown to be recessive to normal flowers and controlled by a single gene. To develop a DNA marker for selection of the long-lasting flower phenotype, we carried out a multiplex-PCR approach to detect the ap3 mutant allele related to long-lasting flower traits, and investigated the flower phenotypes in crossed progenies of 23 cross combinations and 245 individuals. The normal flower phenotype individuals in the crossed progenies were homozygous for the normal allele or heterozygous for the normal allele and the ap3 mutant allele. On the other hand, the long-lasting flower phenotype individuals in the crossed progenies were homozygous for the ap3 mutant allele of long-lasting cultivars. These results support the idea that the long-lasting flower trait is caused by a mutation in the AP3 homolog, and it has been newly clarified that any combination of these mutant alleles in long-lasting flower cultivars has the long-lasting flower phenotype. In conclusion, our data indicate that efficient selection of individuals with long-lasting flowers will be possible by using selection DNA markers linked to the long-lasting flower trait.