Trees growing in wetlands develop adventitious roots from the trunk during the rainy season and adapt to the flooded environment by forming primary (schizogenous or lysigenous) and secondary aerenchyma in the roots. Therefore, it is necessary to clarify the formation process of each type of aerenchyma in these adventitious roots. In this study, saplings of Syzygium kunstleri (King) Bahadur and R.C.Gaur were grown under four different treatments, and a total of 12 adventitious roots generated from trunks were used to clarify the distribution of each aerenchyma type in the roots using light or epi-florescence microscopy. Schizogenous aerenchyma was observed in the root tips where the root color was white or light brown, whereas lysigenous aerenchyma was found at some distance from the root tip where the root color gradually changed from light to dark brown. The secondary aerenchyma and periderm were observed in dark brown parts near the root base. None or only one layer of phellem cells was detected in the white roots near the root tip, but dark brown roots near the root base had at least three layers of phellem cells. Considering these results, oxygen transportation may occur between primary and secondary aerenchyma at the point where two or more layers of phellem cells are formed.

Strain KFRI 723 was used for the cultivation of fruit body to promote the production of b-glucan induced by the elicitor using physical stimulation in the superior cultivated fruit body. Three different elicitor treatments on the physical stimulation (UV, temperature, and harvest time) were treated on the primodia of fruit body. Elicitor controlled by UV light has an effect on the change of the b-glucan contents in flabellae and stipe of cauliflower mushroom, both parts have the highest concentration of b-glucan in strains irradiated by UV for 10 min: 41.36 ± 2.96% of flabellae and 42.16 ± 2.90% of stipe. Both flabellae and stipe represented b-glucan contents in order of low (10 ± 1 C) -mid (21 ± 1 C; control) -high temperature (25 ± 1 C). In the different harvest time, the b-glucan contents of flabellae and stipe show high contents at 21st and 26th day and decreased since 31st day of harvesting. ARTICLE HISTORY

Recent studies based on morphological characteristics and molecular analyses have revealed that the characteristics of Sparassis crispa from Asia are not concordant with those of collections from Europe and North America. Consequently, the Asian isolate was redefined as Sparassis latifolia. This study is the first report of Sparassis latifolia collected in Korea. The taxonomic relationships and replacement of Sparassis species were inferred from a comparison of the morphological characteristics and by molecular sequence analysis of the internal transcribed spacer (ITS) rDNA regions. In particular, this study focused on the phylogenetic relationships inferred from the biogeographical distribution of isolates within the genus Sparassis.

Cauliflower mushroom (Sparassis latifolia or S. crispa) is popular for food and medicine. Importance of new varieties of Sparassis was raised and studied widely by protection system of UPOV. In this study, 10 crossbred strains of Sparassis latifolia that specifically expressed distinctive features during basidiocarp formation and mycelium growth were applied to sawdust medium inoculated with S. latifolia mycelia. The 10 crossbred strains were divided into 3 groups on the basis of morphological (size of marginal wave and basidiocarp color) and genetic characteristics. Each phenotype of the parent and crossbred strains represented 3 marginal wave-sizes (large, medium, and small) and 3 color notations (NN155D, 163C, and 8D). Our result suggests that morphological characteristics of cauliflower mushroom can be affected by various environmental and genetic stimuli under artificial conditions such as crossbreed. Also this research showed genetic differences among breeding isolates and their morphological characteristics were correlated with the molecular data within parent and crossed strain.

Some plant species develop aerenchyma to avoid anaerobic environments. In Syzygium kunstleri (King) Bahadur & R. C. Gaur, both primary and secondary aerenchyma were observed in adventitious roots under hypoxic conditions. We clarified the function of and relationship between primary and secondary aerenchyma. To understand the function of primary and secondary aerenchyma in adventitious roots, we measured changes in primary and secondary aerenchyma partial pressure of oxygen (pO2) after injecting nitrogen (N2) into the stem 0–3 cm above the water surface using Clark-type oxygen microelectrodes. Following N2 injection, a decrease in pO2 was observed in the primary aerenchyma, secondary aerenchyma, and rhizosphere. Oxygen concentration in the primary aerenchyma, secondary aerenchyma, and rhizosphere also decreased after the secondary aerenchyma was removed from near the root base. The primary and secondary aerenchyma are involved in oxygen transport, and in adventitious roots, they participate in the longitudinal movement of oxygen from the root base to root tip. As cortex collapse occurs from secondary growth, the secondary aerenchyma may support or replace the primary aerenchyma as the main oxygen transport system under hypoxic conditions.