Performance of herbaceous Evolvulus pilosus on urban green roof in relation to substrate and irrigation

Rooftop gardening (or green roof establishment) is an urban greening afforestation method that has many environmental, economic, and urban landscaping benefits. For rooftop vegetation, stressful environments that include heat, strong winds, sunshine, and drought prevent many plants from growing well, especially in shallow soil. To establish low cost urban rooftop gardens with a low weight substrate in the summer, we evaluated the green coverage and growth of a suitable groundcover ornamental plant, blue daze (Evolvulus pilosus). Blue daze was used as rooftop vegetation in a shallow substrate (10 cm thick) on the flat rooftop of a four-story building in the middle of Kobe city, Japan, which has a temperate and humid climate. On average, the diurnal maximum temperatures and the total amounts of precipitation during each planting experiment between July and September were 30.8 °C and 247 mm in 2008 and 33.2 °C and 458 mm in 2009, respectively. Three different types of planting substrates (AS, amended soil, TM, turf mat as a dried-up blocks of sod, and FBA, furnace bottom ash) were tested to determine how they influenced plant cover, flowering, and growth. We evaluated the physical and chemical properties of the substrates that were used to establish the rooftop greeneries. In addition, the economy, ornamental and ecological values, reuse of material, and low rooftop weight burdens of the substrates were evaluated. The greatest blue daze ground cover occurred on the TM substrate (relative to the AS and FBA substrates) approximately three months after transplanting. The blue daze actively bloomed on all substrates throughout midsummer. However, alternate day irrigation largely reduced their shoot growth and flowering relative to daily irrigation. The AS and TM substrates had suitable physicochemical properties for use as planting substrates and had ideal solid, liquid, and vapor phase distributions and high water and nutrient holding capacities. FBA was a poor substrate with very low water and nutrient retention capacities, which resulted in depressed plant growth, especially under low watering conditions. To recycle FBA efficiently as a shallow low-cost planting substrate for rooftop gardening, the addition of coated fertilizers and organic matter to FBA should be considered to improve its water and nutrient holding capacities.     

Variation of indole acetic acid (IAA) amounts in cambial-region tissues in 7- and 24-year-old sugi (Cryptomeria japonica) trees

Recently, breeding programs have attempted to produce high growth rates for shorter rotation cycles in plantation trees. In these trees, the ratio of juvenile wood increases; thus, the juvenile wood properties should be improved for structural use. To this end, it is important to understand the influences on juvenile wood properties precisely. In this study, we report on the indole acetic acid (IAA) amounts of juvenile sugi (Cryptomeria japonica) trees in September and compare the IAA amounts to those in mature trees. The IAA amounts at the lower trunks in juvenile trees were significantly larger than those in mature trees and the IAA amounts decreased with tree height. In each stand, except a mature tree stand, there is no significant effect of IAA amounts on latewood width and MFA. However, put together all samples, the latewood width and MFA increased with IAA amounts in samples with IAA <200 ng/cm². The samples at lower trunk in juvenile trees had significantly larger IAA amounts, larger MFA and larger latewood width than the samples in mature trees (p < 0.01). The very large IAA amounts may have a certain relation with juvenile wood properties.     

The role estrogens play in sex differentiation and sex changes of fish

Using genetically controlled all-female and all-male tilapia (Oreochromis niloticus), the role steroid hormones play in the sex differentiation was analyzed histologically, ultrastructurally, immunohistichemically and experimenntally. The results strongly suggest that endogenous estrogen acts as an ovarian inducer, and that the lack of steroid hormone including androgen is important for testicular differentiation. Moreover, the roles of steroid hormones in protogynous sex change of three-spotted wrasse (Halichoeres trimaculatus) and saddleback wrasse (Tharassoma duperrey) were examined. The results strongly support the hypothesis that the endogenous estrogen plays an important role in protogynous sex change.     

Diurnal variation of tryptic activity in larval stage and development of proteolytic enzyme activities of malabar grouper (Epinephelus malabaricus) after hatching

Diurnal variation in tryptic activity and developmental changes in proteolytic enzyme activities of malabar grouper larvae (Epinephelus malabaricus) were examined. Five different groups were prepared for the experiment of diurnal variation of tryptic activity in larvae: larvae were fed Thai-type rotifers Brachionus rotundiformis from the time of mouth opening, fed rotifers from 6 h after mouth opening, 12 h, 24 h and not fed rotifers (starved control). The experimental tanks were placed in temperature-controlled baths at 28 °C under 24 h light. Developmental changes in proteolytic activity of trypsin and pepsin-like enzyme were measured from hatching to 57 days after hatching (DAH).

The tryptic activity of all fed groups showed the same pattern, and the diurnal variation of tryptic activity was clearly observed from 3 to 6 DAH. The highest tryptic activities were found at 19:00, and the activities were lowest from 01:00 to 07:00. In contrast, that of non-fed larvae was low compared to the fed groups, however the diurnal variation of tryptic activity was shown same tendency to the fed groups. Interestingly, both groups (fed and non-fed) were exhibited a circadian rhythm under the 24 h light conditions and delaying of first-feeding. Tryptic activity of larvae notably increased from 40 to 45 DAH and markedly decreased at 52 DAH. In contrast to the tryptic activity, that of pepsin-like enzyme clearly increased from 47 to 51 DAH. The results suggest that a functional change of protein digestion occurs from 40 to 50 DAH related with metamorphosis in malabar grouper. These results could contribute to determining appropriate feeding schedules, such as feeding time, frequency and optimal time to change food items, in mass-scale production of the present species.     

Reactivation of the paternal X chromosome in early mouse embryos

It is generally accepted that paternally imprinted X inactivation occurs exclusively in extraembryonic lineages of mouse embryos, whereas cells of the embryo proper, derived from the inner cell mass (ICM), undergo only random X inactivation. Here we show that imprinted X inactivation, in fact, occurs in all cells of early embryos and that the paternal X is then selectively reactivated in cells allocated to the ICM. This contrasts with more differentiated cell types where X inactivation is highly stable and generally irreversible. Our observations illustrate that an important component of genome plasticity in early development is the capacity to reverse heritable gene silencing decisions.