Control of Flowering and Runnering in Strawberry

Strawberry flowering physiology has engaged the interest of researchers for almost a century after the initial reports demonstrating the photoperiodic control of flowering and N egetative reproduction through stolons called runners. Most strawberries possess a seasonal flowering habit with flower initiation occurring under short days in autumn and flowering during the following spring. Also perpetual flowering genotypes are known in diploid woodland strawberry (Fragaria vesca L.) and octoploid garden strawberry (F. x ananassa Duch.), and recent research have shown that this trait has evolved independently in different species. Studies in the perpetual flowering mutant of woodland strawberry led to the identification of TERMINAL FLOWER1 (FvTFL1) as a major floral repressor causing the seasonal flowering habit in this species and demonstrated that recessive mutation in this gene leads to perpetual flowering. This breakthrough opened an avenue for molecular understanding on the control of flowering by different environmental signals. Different loci control perpetual flowering in garden strawberry including one dominant major locus and additional environmentally regulated epistatic loci. The major gene is called Perpetual Flowering Runnering (PFRU) because it also reduces the number of runners. Growth regulator applications initially demonstrated the role of gibberellin in the control of runner formation, and molecular understanding on the role of gibberellin biosynthesis and signaling in this process has started to emerge. Here, we present current understanding and major open questions on the control of flowering and runnering in strawberries. In order to understand the control of flowering in the context of perennial growth cycle, we also discuss current knowledge on the control of dormancy.Peer reviewe

Fragaria vesca CONSTANS controls photoperiodic flowering and vegetative development

According to the external coincidence model, photoperiodic flowering occurs when CONSTANS ( CO) mRNA expression coincides with light in the afternoon of long days (LDs), leading to the activation of FLOWERING LOCUS T (FT). CO has evolved in Brassicaceae from other Group Ia CO-like (COL) proteins which do not control photoperiodic flowering in Arabidopsis. COLs in other species have evolved different functions as floral activators or even as repressors. To understand photoperiodic development in the perennial rosaceous model species woodland strawberry, we functionally characterized FvCO, the only Group Ia COL in its genome. We demonstrate that FvCO has a major role in the photoperiodic control of flowering and vegetative reproduction through runners. FvCO is needed to generate a bimodal rhythm of FvFT1 which encodes a floral activator in the LD accession Hawaii-4: a sharp FvCO expression peak at dawn is followed by the FvFT1 morning peak in LDs indicating possible direct regulation, but additional factors that may include FvGI and FvFKF1 are probably needed to schedule the second FvFT1 peak around dusk. These results demonstrate that although FvCO and FvFT1 play major roles in photoperiodic development, the CO-based external coincidence around dusk is not fully applicable to the woodland strawberry.Peer reviewe

Gonad development and size at maturity of the male mud crab Scylla paramamosain (Forsskål, 1755) in a tropical mangrove swamp

The reproductive traits and size at sexual maturity of the male mud crab Scylla paramamosain were investigated in Pak Phanang mangrove swamps, Thailand. Samples were taken seven times from the local middlemen mud crab traders during June 2006 to January 2008. Gonad development was determined based on histological appearance that was classified into three stages: 1) Immature (Spermatogonia), 2) Maturing (Spermatocytes) and 3) Mature (Spermatids and Spermatozoa). Among the sample population, the highest 72% was under gonad development stage I, whereas mature stage III was only 12%. The size at first maturity was estimated by the external allometric growth and histological observation of gonad. The size at which 50% of individuals attain sexual maturity was estimated by the two mathematical models such as probit analysis and logistic curve. The mean size at first sexual maturity and 50% maturation of male S. paramamosain were 96 mm and 109 mm internal carapace width (ICW) which revealed that 88% individuals were immature. The present result suggested that the minimum legal size of male S. paramamosain capture should be >110 mm ICW

Community-based shrimp stock enhancement for coastal socio-ecological restoration in the Philippines

The reality of declining quality of coastal areas has been evident for many developing countries, especially in Southeast Asia. In the Philippines, rural coastal zones and estuaries are now being characterized by declining wild fisheries resources and degrading environment. This paper presents, as an example, the typical rural coastal towns of New Washington and Batan in Aklan province, Philippines and showcases how the concept of shrimp stock enhancement can provide incentives to restore the environment and provide sustainable fishing livelihood in the area. The New Washington-Batan Estuary in northeast Panay Island, Philippines was a productive fishing ground that has been in a state of degenerating brackishwater fisheries and estuarine environment. Average daily catch composed of various species decreased from 24 kg in 1970s to 0.7 kg at present. Shrimp fisheries, the most important livelihood, declined in quality and quantity. The highly-priced and once very abundant tiger shrimp Penaeus monodon was replaced with smaller-sized and lower-priced species like the Metapenaeus ensis. These can be attributed to the conversion of 76% of mangroves to culture ponds in the past 50 years and more than 400% increase in fishing gears since the 1990s. The need to reduce fishing structures and rehabilitate mangroves is evident. However, these drastic changes directly affect fishers livelihood. This paper explores the prospects of P. monodon stock enhancement as positive reinforcement for the estuary s rehabilitation. Number of gears per fisher may have to be reduced but shrimp catches will be relatively high-priced. Simulations with additional tiger shrimp caught due to stock enhancement show that fishers can increase income by more than 4 times from their current PhP 34 gear-1 day-1. Campaigns on the importance of mangrove especially as shrimp habitat can encourage local communities to reforest the estuary especially in abandoned ponds. With effective management, law enforcement, and sustained support from different sectors, shrimp stock enhancement can be a positive strategy in estuarine rehabilitation and livelihood sustainability in the New Washington-Batan Estuary

Econometric Analysis of the Factors Contributing to the Fish Price increase in Coastal Turfs in Japan: the Case of the income Pooling Fishery for Coastal Shrimp Sakuraebi (Sergia Lucens)

While right-based managements have often been encouraged as effective management tools, few studies presented an empirical analysis on the effects of those systems. This paper focuses on a special form of Territorial Use Rights Fisheries called an income pooling system, and examines the effects of the system empirically. Income pooling system is a unique Japanese fishery management system where fishermen harvest fish cooperatively, and divide the total income based on a certain rule, in many cases equal distribution. The increase of fish price through control on landing amount and improvement of quality of fish is regarded as the main effect of the system in earlier studies, so we estimated the magnitude of the impact of two factors on the price of fish with econometric method. The results show that the two factors in fact have significant effects for the price changes. Also, the effect of the improvement of quality for the price is not negligible compared to that of control on landing amount. These results suggest that to improve the income of fishermen, the policy encouraging fishermen to improve the quality of fish is effective. This study can be regarded as one of the first attempts to use economic analysis to evaluate the economic performance of fishery management system

Coastal Marine Protected Areas in Japan and their Institutional Characteristics

A survey was conducted to create a comprehensive list of marine protected areas (MPAs) in Japan. There exist more than 1,000 fishery cooperatives in Japan, and many of them have established no-take zones for many years. Such zones are usually not reported to the government and, therefore, the complete picture of the MPAs in Japan has been largely unknown until now. Information on such local MPAs was collected through various sources, and a list of more than 1,000 MPAs was produced. Many of them take the style of self-imposed voluntary regulations. Nonetheless, it was suggested that free-riders of the conservation activities were uncommon. This is because agreements are usually made to maximize the benefit of the group of fishers and each member of the group monitors the compliance status of other members. The government has provided territorial use right for fishers, and this could have helped maintain such a selfgovernance framework

Additive QTLs on three chromosomes control flowering time in woodland strawberry (Fragaria vesca L.)

Flowering time is an important trait that affects survival, reproduction and yield in both wild and cultivated plants. Therefore, many studies have focused on the identification of flowering time quantitative trait locus (QTLs) in different crops, and molecular control of this trait has been extensively investigated in model species. Here we report the mapping of QTLs for flowering time and vegetative traits in a large woodland strawberry mapping population that was phenotyped both under field conditions and in a greenhouse after flower induction in the field. The greenhouse experiment revealed additive QTLs in three linkage groups (LG), two on both LG4 and LG7, and one on LG6 that explain about half of the flowering time variance in the population. Three of the QTLs were newly identified in this study, and one co-localized with the previously characterized FvTFL1 gene. An additional strong QTL corresponding to previously mapped PFRU was detected in both field and greenhouse experiments indicating that gene(s) in this locus can control the timing of flowering in different environments in addition to the duration of flowering and axillary bud differentiation to runners and branch crowns. Several putative flowering time genes were identified in these QTL regions that await functional validation. Our results indicate that a few major QTLs may control flowering time and axillary bud differentiation in strawberries. We suggest that the identification of causal genes in the diploid strawberry may enable fine tuning of flowering time and vegetative growth in the closely related octoploid cultivated strawberry.Peer reviewe

Introduction for Fisheries and Aquatic Biology

Chapter I. Aquatic Environment. Ken FURUYA and Ichiro YASUDA : chapter_1.pdfChapter II. Biology and Ecology of Aqua-Shere. Toyoji KANEKO, Katsumi TSUKAMOTO, Atsushi TSUDA, Yuzuru SUZUKI and Katsufumi SATOH : chapter_2.pdfChapter III. Aquatic Resource and Production. Ichiro AOKI, Kazuo OGAWA, Taku YAMAKAWA and Tomoyoshi YOSHINAGA : chapter_3.pdfChapter IV. Chemistry of Aquatic Organism and Their Utilization. Hiroki ABE, Shugo WATABE, Yoshihiro OCHIAI, Shigeru OKADA, Naoko YOSHIKAWA, Yoshiharu KINOSHITA, Gen KANEKO and Shigeki MATSUNAGA : chapter_4.pdfChapter V. Relation between Aqua-Shere and Human Life. Hisashi KUROKURA, Hirohide MATSUSHIMA, Shingo KUROHAGI, Haruko YAMASHITA, Akinori HINO, Kazumasa IKUTA, Satoquo SEINO, Masahiko ARIJI, Ken FURUYA, Junichiro OKAMOTO and Nobuyuki YAGI : chapter_5.pdfPart of "Introduction for Fisheries and Aquatic Biology

Using Light to Improve Commercial Value

The plasticity of plant morphology has evolved to maximize reproductive fitness in response to prevailing environmental conditions. Leaf architecture elaborates to maximize light harvesting, while the transition to flowering can either be accelerated or delayed to improve an individual's fitness. One of the most important environmental signals is light, with plants using light for both photosynthesis and as an environmental signal. Plants perceive different wavelengths of light using distinct photoreceptors. Recent advances in LED technology now enable light quality to be manipulated at a commercial scale, and as such opportunities now exist to take advantage of plants' developmental plasticity to enhance crop yield and quality through precise manipulation of a crops' lighting regime. This review will discuss how plants perceive and respond to light, and consider how these specific signaling pathways can be manipulated to improve crop yield and quality