Effect of Ultraviolet Radiation Environment on Leaf Quantum Efficiencies and Photosynthesis for Tropical and Temperate Species

ABSTRACT

Ultraviolet radiation has detrimental effects on plants and levels are expected to rise through mid-century. Photosystem II is the most vulnerable site in chlorophyll affecting productivity. The purpose of this study was to evaluate leaf-level interactions with UV radiation in tropical and temperate crops. The species sampled were (1) citrus, (2) banana, (3) coffee, (4) pineapple, (5) olive, (6) grape, (7) apple, and (8) tobacco. Plants of each species were placed beneath a polycarbonate structure that excluded 98% of UV radiation, but maintained ambient environmental conditions and transmitted 96% PAR (UV– treatment). Plants of each species were maintained nearby under ambient conditions (i.e., without a UV filter; UV+ treatment). The maximum quantum efficiency (F_v/F_m) was measured with and without UV radiation at the time of measurement. Photosynthesis (A) and quantum efficiency (Φ_II) were measured in the same experimental system using only apple, citrus, banana, and coffee. Only banana and coffee did not fully recover their F_v/F_m potential when they had not been previously exposed to UV, indicating that these species probably had not induced background repair mechanisms. The ΔF_v/F_m is small in magnitude for banana and coffee due to UV treatment but when A is measured, the treatment impact has greater magnitude and banana and coffee A do not recover and coffee Φ_II continues to decline while banana Φ_II appears to stabilize. Banana and coffee have the potential to benefit from cultural practices that reduce the UV irradiance to the leaf or canopy surface.     

社会网络、农户感知特征与兰花生产效率分析

基于农户视角,以广东韶关粤台农业合作试验区兰花种植业为例,通过数据包络分析、社会网络分析、多元回归分析等方法,探讨社会网络、农户感知特征与兰花生产效率的关系。结果表明:农户社会网络地位、农业技术培训、农户对兰花的认知等对兰花生产效率的正向影响显著;农户兼业情况对兰花生产效率产生显著负向影响;农户创业能力、受教育程度、种植规模及风险意识等对兰花生产技术效率的影响不显著;试验区特殊的地域文化在促进兰花生产效率提高的同时,也带来了一些消极影响。     

现代销售渠道对技术效率的影响——基于江苏省草莓种植户调研

随着高质量农产品需求逐渐增加,以农超对接、农产品电商和龙头企业模式为代表的现代销售渠道逐渐发展。现代销售渠道具有价格稳定、供应关系稳定、质量要求高等特点,能够提高农户的整体生产环节技术效率。本文基于江苏省358份草莓种植户调研数据,运用SFA-PSM方法,研究参与现代销售渠道对农户技术效率的影响。结果表明:传统销售渠道与现代销售渠道的农户在投入上存在显著差异,参与现代销售渠道能提高9%左右的技术效率,显著提高农户收益。据此提出建议,相关部门应大力扶持现代销售渠道发展,连接农户与市场,形成稳定的供销关系,提高草莓种植户的技术效率。     

Ecosystem services as the products of land system dynamics: lessons from a longitudinal study of coupled human–environment systems

Context

We address understanding of whole-system and landscape-based approaches to the ecosystem services framework by considering the supply of provisioning services and the dynamics of agricultural land use in Scotland between 1940 and 2016.

Objectives

To characterise and understand the dynamics of change in provisioning services from agriculture in Scotland over the period 1940–2016. To identify ways in which funds of capitals and flows of inputs and output ecosystem goods are linked to land management practices and policies at a national scale.

Methods

Data describing agricultural land use, production, financial and energy inputs and outputs, and drivers of change in land use in Scotland are analysed with an accounting framework that links funds of natural, human, physical and financial capital, with flows of goods and services. Flow–fund ratios are used as benchmarks of system performance and dynamics.

Results

Scotland’s agriculture has modernised since 1940 and become more efficient in conversion of resources, with a consequent increase in delivery of provisioning goods and services. Although the energy ratio, and flow of goods per unit hectare and per unit labour have increased, the inputs necessary to maintain those flows of ecosystem goods are also increasing, even as their relative economic costs decrease. Increases in use of fertiliser suggests that production from the soil, as a natural capital fund, is not being conserved without a large, and increasing, input. Analysis of the complexity of the coupled agricultural land system also suggests that land management rather than biodiversity is a necessary subject for evaluation of provisioning services from agriculture. Understanding of ecosystem services based on accounts that integrate inputs, outputs and flows from funds of natural, human, social, financial and physical capitals, provides a process-based foundation for improved understanding of ecosystem services and human–environmental relationships.

Conclusions

Adopting an accounting approach for understanding the role of agricultural land use for supply of provisioning services, and particularly examining a long time-series of accounts, enables understanding of land changes and underlying drivers, as well as the contribution of cultural and other aspects of human systems coupled with environment systems. Accounting for ecosystem services using costs as well as benefits, and use of metrics beyond financial benefit, supports debate and evaluation of trade-offs between services and has direct relevance for decision- and policy-making.

     

Optimising parameters for biolistic gun-mediated genetic transformation of tea [Camellia sinensis (L.) O. Kuntze]

Summary

Genetic improvement of tea through breeding is difficult. Therefore, transgenic tea plants expressing the osmotin gene from Nicotiana tabacum were produced using parameters optimised for biolistic-gun mediated transformation. During optimisation, a total of 4,500 somatic embryos were bombarded using nine combinations of variable target distances and burst pressures, while keeping the gap distance (0.6 cm) and macrocarrier flight distance (16 mm) constant.A total of 90 independent, PCR-positive lines were generated. Southern hybridisation confirmed integration of the osmotin gene in 26 out of 27 PCR-positive lines (three independent lines from each of the nine parameter combinations were selected at random). Statistical analysis revealed that the efficiency of transgene integration was significantly affected by target distance. Only those lines derived from somatic embryos bombarded with 1.0 µg plasmid DNA using a 7.58 MPa burst pressure and 9-cm target distance showed osmotin expression. This was evident from strong northern hybridisation and RT-PCR signals. Leaves of 4-year-old transgenic plants growing in a contained polythene tunnel showed improved osmotic adjustment in response to osmotic stress imposed by NaCl. The osmotic potentials of transgenic leaves immersed in 100 mM or 200 mM NaCl solutions were more negative than those of non-transformed control leaves.     

Application of a dynamic model using agronomic and economic data to evaluate the sustainability of the olive grove landscape of Estepa (Andalusia,Spain)

Context

In the Andalusia region (Spain), olive grove agro-systems cover a wide area, forming social-ecological landscapes. Recent socioeconomic changes have increased the vulnerability of these landscapes, resulting in the abandonment and intensification of farms. The provision of the main ecosystem services of these landscapes have thus been degraded.

Objectives

To analyse the sustainability of an olive grove social-ecological landscape in Andalusia. Specifically, to develop a quantitative model proposing land planning and management scenarios, considering abandonment, production and economic benefits of olive crops in different conditions of erosion and management.

Methods

We applied a dynamic model using agronomic and economic data, to evaluate different types of olive management. We considered different levels of erosion, the loss of production related to this erosion, and useful life spans for each type of management. We simulated scenarios for the long-term assessment of dynamics of crops, abandonment rate, production and benefits.

Results

(a) There was a loss of productive lands and benefits in the medium term in the more intensive crops. (b) Scenarios that partially incorporated ecological management proved to be more sustainable without economic subsidies. (c) The spatial combination of integrated, intensive and ecological plots was sustainable, and was well balanced from an economic, productive and ecological point of view.

Conclusions

Scenarios that partially incorporate ecological management allowed the best economic and environmental balance. However, to ensure the sustainability of olive landscapes, farmers should be financially rewarded for their role in the conservation of ecosystem services through landscape stewardship and direct environmental payments.

     

Energy Analysis and Emissions of Greenhouse Gases of Pomegranate Production in Antalya Province of Turkey

In this study, energy use patterns and the functional relationship between energy inputs and output for pomegranate production were investigated in Antalya province in Turkey. It further objective to identify greenhouse gas (GHG) emissions in pomegranate production. Data were obtained from 75 farms using face-to-face interview method. The results indicated that 50,605.5?MJ ? ha^?1 of total energy input was required for 76,252.3?MG ? ha^?1 pomegranate energy output. 1.51 unit energy output was provided by using 1 unit energy input. 1 unit energy output and 1?kg pomegranate require 0.66 unit and 2.57?MJ energy input, respectively. The average CO₂ emission amounts were also calculated to be 1.73?t CO₂ per hectare and 88.1?kg CO₂ per 1000?kg pomegranate production. Electricity, fertilizers and pesticides were the highest contributors to GHG emissions. Both total energy input usage and GHG emission amounts have been found to be decreasing as the farm size increases. Increasing scale of pomegranates orchards will not only increase energy efficiency and productivity but also decrease environmental pollution and damages. The regression analysis revealed that, excessive use of machinery and fuel inputs results in a decline in energy production in pomegranate.     

Effects of post-harvest salicylic acid treatment on fruit quality and anti-oxidant metabolism in pineapple during cold storage

Summary

Pineapple (Ananas comosus L. ‘Comte de Paris’) fruit at commercial maturity (180 fruit per treatment, three replicates) were immersed in 0, 1.0, 3.0, or 5.0 mM salicylic acid (SA) for 15 min, then stored at 10ºC and 90% relative humidity (RH) for 20 d. After 20 d in cold storage, they were moved to 20ºC for 2 d to simulate shelf-life. Physiological and biochemical responses were studied. The results showed that the 3.0 or 5.0 mM SA treatments lowered the internal browning (IB) index, while the 5.0 mM SA treatment decreased the soluble solids content (SSC), titratable acidity (TA), and soluble sugar content, but increased ascorbic acid (AsA) levels at the end of shelf-life. Furthermore, during cold storage, all SA treatments significantly decreased the rate of tissue respiration in pineapple fruit. SA at 5.0 mM significantly decreased the activities of peroxidase (POD), polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL), but increased the activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX) compared with the non-SA treated (untreated) controls. Overall, these results indicate that post-harvest treatment with 5.0 mM SA delayed the occurrence of IB in pineapple, extended its shelf-life, and maintained fruit quality during cold storage.     

Monitoring the genetic fidelity of micropropagated plantlets of Spondias mangifera Willd. using RAPD marker assays

Summary

Random amplified polymorphic DNA (RAPD) markers were used to screen for clonal fidelity in in vitro-propagated plantlets of Spondias mangifera produced through direct organogenesis. One micropropagated plantlet was selected at random after each sub-cultural passage (six sub-cultures), along with the donor plant, for RAPD marker analysis. Twenty-five RAPD primers were used to study genetic similarities or dissimilarities with the mother plant as well as among the regenerated plants. Individual primers showed that the same pattern of RAPD markers was shared by all in vitro-propagated plantlets and the mother plant. No variation was observed among the micropropagated progenies. Thus, in vitro-regenerated plantlets of S. mangifera were clonally uniform and genetically stable.     

Grouping of banana clones based on genomic groups,ploidy, and seasons of planting for sucker production in Musa spp.

ABSTRACT

Sucker production of important clones belonging to different ploidy levels and genomic groups were assessed in three different planting seasons at Kerala Agricultural University, Thrissur, India. The study revealed that morphological characters such as plant height, collar girth, and total number of leaves recorded very strong, significant, and positive correlation with sucker production characters but negative correlation was observed with average leaf production interval and bunch weight. The number of dead suckers was found to be positively correlated with plant height, collar girth, “D” leaf area, bunch weight, and average leaf production interval. In a cluster analysis, six banana varieties that were planted in different three seasons (18 entries) and their pooled data (6 entries) were grouped into four distinct clusters each. In factor/principle component analysis, the first three major factors/principle components amounted to a total of 85.9% of the variability. The communality values of the factor analysis revealed that collar girth was the major relative contributory trait for deciding the sucker yield and production in banana.

Abbreviations: EVS: Early vegetative stage; AVS: Active vegetative stage; FBI: Flower bud initiation; FBD: Flower bud differentiation; PCA: Principle component analysis; FA: Factor analysis     

Modeling a cross-ecosystem subsidy: forest songbird response to emergent aquatic insects

Context

Resource movements across ecosystem boundaries are important determinants of the diversity and abundance of organisms in the donor and recipient ecosystem. However the effects of cross-ecosystem movements of materials at broader spatial extents than a typical field study are not well understood.

Objectives

We tested the hypotheses that (1) variation in abundance of 57 forest songbird species within four foraging guilds is explained by modeled emergent aquatic insect biomass inputs from adjacent lakes and streams and (2) the degree of association varies across foraging guilds and species within guilds. We also sought to determine the importance of emergent aquatic insects while accounting for variation in local forest cover and edge.

Methods

We spatially modeled the degree to which distribution and abundance of songbirds in different foraging guilds was explained by modeled emergent aquatic insect biomass. We used multilevel models to simultaneously estimate the responses of species in four different insectivorous guilds. Bird abundance was summarized from point counts conducted over 24 years at 317 points.

Results

Aerial insectivores were more abundant in areas with high estimated emergent insect biomass inputs to land (regression coefficient 0.30, P?<?0.05) but the overall abundance of gleaners, bark-probers, and ground-foragers was not explained by estimated emergent insect abundance. The coursing aerial insectivores had the strongest association with emergent insects followed by willow flycatcher, olive-sided flycatcher, and alder flycatcher.

Conclusions

Modeling cross-ecosystem movements of materials at broad spatial extents can effectively characterize the importance of this ecological process for aerial insectivorous songbirds.

     

Obtaining and characterizing Pleurotus ostreatus strains for commercial cultivation under warm environmental conditions

Pleurotus ostreatus strains obtained by interbreeding were cultivated under warm conditions (27 °C), with the aim to identify germoplasm adequate to commercial production. Based on the radial growth rate of monokaryotic mycelia isolated from two P. ostreatus strains, a culture isolate was selected from each type of compatibility, and interbred to obtain 16 strains. Pasteurized barley straw was used as the substrate for mushroom production. The mean biological efficiency of the strains was 84.17% and the production rate was 1.76%. In vitro laccase activity was tested for both parental strains and the four most productive strains of progeny. The mean enzyme activity of the strains was 1.21 μg mol/disc/ABTS oxidized. These results show the high potential of these strains for their use in substrate delignification and the production of basidiocarps under natural environmental conditions of warm regions.     

Determining the Energy Usage Efficiency of Walnut (<Emphasis Type="Italic">Juglans Regia</Emphasis> L.) Cultivation in Turkey

The aim of this study is to reveal the energy balance of walnut in Central Anatolian Region in Turkey. This study has been conducted at the walnut cultivating facilities during the 2014–2015 production season in K?r?ehir, Konya, Nev?ehir and Ni?de provinces of Central Anatolian Region in Turkey, where walnut cultivation is intense. In the study, a total of 28 walnut cultivation facilities, yielding walnut, have been selected through Neyman method and surveys and observations have been performed in these facilities. The agricultural input energies and output energies used in walnut cultivation have been calculated to define the energy use efficiency. According to the study findings, the energy inputs in walnut cultivation are calculated respectively 17,851.33?MJ ha^?1 (74.40%) chemical fertilizer energy, 2229.87?MJ ha^?1 (9.29%) fuel energy, 1640.64?MJ ha^?1 (6.83%) irrigation water energy, 1539?MJ ha^?1 (6.41%) machine energy, 508.02?MJ ha^?1 (%2.11) chemical energy, 180.35?MJ ha^?1 (0.75%) human labour energy and 43.33?MJ ha^?1 (0.18%) farm manure energy. Production outputs have been calculated as 14,679.52?MJ ha^?1. Following the energy calculations, the output/input ratio, specific energy, energy efficiency and net energy calculations have been calculated respectively as 0.61, 30.20?MJ kg^?1, 0.03?kg MJ^?1 and ?9313.02?MJ ha^?1. Benefit-cost ratio was calculated as 1.88, by dividing the gross value of production by the total cost of production per hectare in walnut production.     

A new framework of spatial targeting for single-species conservation planning

Context

Organisations acting to conserve and protect species across large spatial scales prioritise to optimise use of resources. Spatial conservation prioritization tools typically focus on identifying areas containing species groups of interest, with few tools used to identify the best areas for single-species conservation, in particular, to conserve currently widespread but declining species.

Objective

A single-species prioritization framework, based on temporal and spatial patterns of occupancy and abundance, was developed to spatially prioritize conservation action for widespread species by identifying smaller areas to work within to achieve predefined conservation objectives.

Methods

We demonstrate our approach for 29 widespread bird species in the UK, using breeding bird atlas data from two periods to define distribution, relative abundance and change in relative abundance. We selected occupied 10-km squares with abundance trends that matched species conservation objectives relating to maintaining or increasing population size or range, and then identified spatial clusters of squares for each objective using a Getis-Ord-Gi* or near neighbour analysis.

Results

For each species, the framework identified clusters of 20-km squares that enabled us to identify small areas in which species recovery action could be prioritized.

Conclusions

Our approach identified a proportion of species’ ranges to prioritize for species recovery. This approach is a relatively quick process that can be used to inform single-species conservation for any taxa if sufficiently fine-scale occupancy and abundance information is available for two or more time periods. This is a relatively simple first step for planning single-species focussed conservation to help optimise resource use.

     

Characterisation of novel simple sequence repeat (SSR) markers for melon (Cucumis melo L.) and their use for genotype identification

Summary

The objectives of this study were to provide a set of useful simple sequence repeat (SSR) markers, to characterise them, and to demonstrate their ability to detect polymorphisms across diverse genotypes of melon. A total of 183 SSR markers were developed in melon from libraries enriched for (CA)_n, (CT)_n, (AAG)_n, and (ATG)_n repeats. The efficiency of marker development was highest in the CT library. The efficiencies of the CA, AAG, and ATG libraries were similar, and approx. 60% of that of the CT library. Dinucleotide motifs were observed more frequently than trinucleotide motifs. Approx. 50% of CA/TG motifs and approx. 30% of CT/AG motifs exhibited a repeat number greater than ten, while most other motifs showed a repeat number of less than ten. Fifty primer pairs were selected at random and used to evaluate polymorphisms among 19 melon accessions representing seven varieties. All 50 markers were amplified successfully in the majority of accessions, and 42 markers were polymorphic among the 19 melon accessions. All polymorphic markers could detect variation between at least two accessions belonging to the same variety, with polymorphic information content values ranging from 0.10 - 0.96. The SSR markers developed were variable and transferable and will be valuable molecular tools in melon breeding programmes.     

菠萝微卫星指纹图谱的构建

初步构建了菠萝种质的SSR指纹图谱,为菠萝种质鉴定提供了依据.从菠萝EST-SSR开发的20对微卫星引物扩增31份不同的菠萝种质,筛选出能够稳定扩增且带型差异明显的SSR引物.挑选5对多态性高、分辨率高、重复性好的SSR引物对,作为标准引物对材料进行扩增.每对引物得到的多态性带数8~15个,平均为11条;引物的多态信息...     

Pollinator selection in kiwifruit (Actinidia deliciosa)

SUMMARY

Pollinator performance was evaluated in kiwifruit to select pollinators for cv. Hayward adapted to the cultural conditions of southern Europe. Flowering time was determined in forty male seedlings. From, these, nine were selected for having a flowering period overlapping with ‘Hayward’. In these nine males, as well as in the commercial pollinators‘Matua’ and Tomuri’, the production of pollen was studied over two years, investigating pollen quantity through flower density and pollen production per flower. Likewise, in vitro pollen viability and its in vitro germination were recorded to study pollen quality. Finally, in vivo pollen performance was studied through fruit set and fruit characteristics in controlled hand pollinations. Two males have been selected with a flowering period coincident with ‘Hayward’, which produce more than twice as much germinable pollen than commercial pollinators. Whilst there were no significant differences in pollen quality or in fruit production, clear differences existed for pollen quantity in terms of both flower density and pollen production per flower. As pollen quantity, together with flowering time, can be easily evaluated at an early stage, this is encouraging for future selection ofkiwifruit pollinators.     

Genetic diversity analysis of Phalaenopsis ‘Frigdaas Oxford’ using SRAP markers with reference to those genes responsible for variations in the pigmentation of petals and sepals

Summary

A selfed progeny from Phalaenopsis ‘Frigdaas Oxford’, with yellow flowers and red-purple blotches, was established. Individual plants varied greatly in terms of the number, size, and distribution pattern of the red-purple blotches. Sequence-related amplified polymorphism (SRAP) markers were used to analyse 159 individual plants in the progeny, and 14 polymorphic primer combinations were selected from the 594 SRAP primer combinations tested. In total, 80 polymorphic bands were produced using these primer combinations. On average, each primer pair combination amplified 80.1% polymorphic bands. An UPGMA dendrogram and a principal coordinate analysis (PCA) showed that the 159 individual plants selected could be divided into 12 clusters, including a cluster that consisted of plants in which the petals and sepals were fully red-purple in colour. Plants in which the petals and sepals had large red-purple blotches were genetically closer to the latter cluster than were those plants in which the blotches were small, indicating that the SRAP markers could be used efficiently to identify genetic variation in a Phalaenopsis population with respect to flower colour. Furthermore, 45 unique genes identified by SRAP from the selfed progeny population were sequenced. These data suggest that SRAP markers for the pattern of pigmentation in the petals and sepals of Phalaenopsis may be used in breeding Phalaenopsis for specific patterns of flower pigmentation.     

The effects of permanent magnetic fields on in vitro growth of Phalaenopsis plantlets

Summary

This is the first study to address the effects of permanent magnetic fields (MFs) on the in vitro growth of Phalaenopsis plantlets. Uniform Phalaenopsis Gallant Beau ‘George Vazquez’ plantlets, each with two leaves and two roots, and each approx. 2 cm in height, were excised from a mass of protocorm-like bodies (PLBs) after 3 months of sub-culture. The plantlets (n = 21) were cultured in a film culture system (‘Miracle Pack’^®) under MFs of different intensity: 0.10, 0.15, or 0.20 Tesla (T). Each culture vessel at each MF intensity was cultured on the North (N) or South (S) poles of specialised magnets. The 0.15 T MF was also applied for different lengths of time (1, 2, or 3 months) at both the N and S poles. Control plantlets were simply exposed to the naturally-occurring geo-MF, and not to any induced MF. All MFs tested had a positive influence on shoot and root development, but did not influence chlorophyll contents. Among all the intensities and polarities of MF tested, 0.10 T – S had the greatest positive influence on specific growth parameters of Phalaenopsis plantlets such as maximum leaf length, root length, fresh weight and dry weight of shoots and roots, and leaf width. Constant exposure to a MF of 0.15 T for 3 months, at either the N or S poles, significantly enhanced the development of plantlets.The results obtained in this study indicate that MFs can have a positive effect on the efficiency and quality of clonal Phalaenopsis plantlets during commercial production. The MFs from commercially-produced permanent magnets enhanced Phalaenopsis plantlet growth significantly and can be used as a novel means to study the effect of MFs on plant growth and development, or to control morphogenesis in limited spaces such as space stations.