Short Shoots Research Articles

Penyimpanan In Vitro Tanaman Obat Daun Dewa melalui Pertumbuhan Minimal

<p class="p1">Daun dewa (<em>Gynura Procumbens</em>) is a medicinal crop commonly used to remedy cancer, diabetes, and dermatitis. It has a bright prospect for future used. Plant preservations through tissue culture is done to anticipate an urgent need. An experiment was carried out to <em>in vitro </em>preservation of Daun Dewa by the minimum growth and regeneration to examine viability of the culture after the preservation. Terminal shoots (±1 cm) were cultured on a 1/2 MS basic medium + paclobutrazol (0, 1, 2, 3, and 4 mg/l) or ABA (1, 2, and 5 mg/l). The trial was arranged in a, completely randomized with 10 replications. The results showed a three-month preservation of the culture on a medium containing ABA inhibited proliferation and expansion of the plant shoots. Increasing ABA concentrations up to 5 mg/l, according to the shoot-growth inhibition, resulted in the height of 0.6 cm. After three month preservation, the shoots were able to produce roots. After 12 month preservation, the optimum capacity of growth inhibition was shown on 1/2 MS medium + ABA (1, 3, and 5 mg/l). The application of paclobutrazol (1, 2, 3, and 4 mg/l) in the medium produced low multiplication level of shoots, the length of the shoots remains higher than those on 1/2 MS medium without paclobutrazol. Seven months after preservation, viability of the plants was still high when cultured on MS medium + 2 mg/l BA combined with paclobutrazol and ABA as previously given. In addition, the rooted culture could be directly acclimatized in the glasshouse. The lowest number of shoot and shortest shoot after 12 month preservation period was found on the medium containing 5 mg/l ABA and 4 mg/l paclobutrazol, this treatment produced two shoots of 4 cm long. The best medium for the explant regeneration after 7 month preservation was MS + 2 mg/l BA. The plant shoots produced roots directly after they were acclimatized in the glasshouse.</p>

Responses and influencing factors of foliar photosynthetic characteristics of <italic>Larix gmelinii </italic>to changing environments

Investigating tree photosynthetic capacity is important for understanding the carbon cycles of terrestrial ecosystems and their responses and adaptation to climatic change. Dahurian Larch ( Larix gmelinii ) is one of the dominant tree species in Chinese boreal forests with a broad bio-geographic range under divergent habitats, and thus an ideal tree species for exploring tree adaptation to environment. In this study, we measured the foliar photosynthesis and associated physiological parameters of 30-year-old Dahurian larch trees from six provenances in a common garden at the Maoershan Forest Ecosystem Research Station in Northeast China for three years (2009–2011). The six provenances were located across the natural distribution range of the larch, spanning approximately 4° in latitude (48°–52°N), 5°C in mean annual temperature ( - 2.3–2.6°C), and 200 mm in mean annual precipitation (425–622 mm). To access the top canopy of the sampled trees, we constructed 15-m-high wooden scaffolds at the site. Three representative trees from each provenance were selected for the measurements per month from mid May to mid September. We measured three fully expanded sunlit fascicles on young short shoots at the top of the canopy of each tree in situ with an infrared gas analyzer. On non-rainy days, light and CO2 response curves were measured between 06:30 and 12:00 hours under optimal conditions. Our goal was to explore impacts of environmental changes on foliar photosynthetic characteristics of the larch and their driving factors. The main results were summarized as follows: (ⅰ) The leaf-area-based maximum net photosynthetic rate ( P max-a), dark respiratory rate ( R a), apparent quantum yield (AQY), maximum rate of carboxylation ( V max), maximum electron transport rate ( J max) and triose phosphate utilization rate (TPU) all increased significantly ( P T s) and aridity index (AI) of the seed-source original sites, while the light compensation point (LCP) and photorespiratory rate ( R p) showed an opposite trend. This suggests that the leaf photosynthetic characteristics genetically adapt to the original site conditions of the tree seed-sources, among which the temperature and precipitation are the major driving factors. (ⅱ) P max-a was positively correlated with AQY, V max, J max, TPU, and leaf nitrogen concentration, but negatively with LCP and R p ( P T s habitats had higher sensitivity of P max-a associated with other characteristics. (ⅲ) P max-a was significantly and positively correlated with 3-day mean temperature, mean monthly temperature, mean growing season temperature, 3-day mean relative humidity, and mean monthly precipitation of the common garden, while the R a showed opposite trends with the environmental factors except for the mean growing season temperature. This indicates that the leaf photosynthetic characteristics acclimate to the environmental conditions of the common garden. However, the trees from higher T s habitats had lower intercepts of the regression equations of P max-a associated with the environmental factors, and had the opposite trends for R a except for the mean growing season temperature. The results suggest that the relationships between foliar photosynthetic characteristics and environment are jointly controlled by both phenotypic acclimation to current site conditions and genotypic adaptation to the original environment of the seed-source. These findings provide insights on understanding the survival, reproduction and distribution of Dahurian larch to changing environments.

Factors affecting fruit set and fruit quality along branch units of different apricot cultivars

ABSTRACTUnderstanding the differences in fruit quality within apricot tree canopies is necessary before developing strategies to reduce variation. Fruit set, fresh weight (FW) and soluble solids and dry matter concentrations (SSC, DMC) were lower, by up to 30%, 28 g, 2.4% and 2.5%, respectively, in fruit from 1-year-old long shoots and terminal spurs or from short shoots and spurs on 4-year-old wood, than on those from 2- and 3-year-old wood, for the six genotypes examined. Genotype, year and wood age affected mealiness, gel development, rubberiness and/or juiciness in fruit after cold storage. Effects of position along the shoot, fruit number and fruiting node leaf area on fruit quality were examined for one cultivar. FW, SSC and DMC were higher in fruit on distal zones of 2-year-old wood, but were lower in fruit from distal zones of 1-year-old wood. Greater fruit number per shoot before thinning decreased FW on 2-year-old wood. On 1-year-old wood, there was an interaction between fruiting node leaf area, position and fruit FW. These results will assist in devising management techniques, such as differential thinning and pruning, to reduce fruit quality variation.

First record of Sphenarion (Czekanowskiales) with epidermal structures from the Middle Jurassic of Inner Mongolia, China

The genus Sphenarion (Czekanowskiales) was first established for some fossil leaves from the Middle Jurassic Yorkshire flora of England. There are relatively few reports of Sphenarion with epidermal structures in the Mesozoic floras of Eurasia since its establishment. In this paper we describe a new species, Sphenarion angustae n. sp., from the Middle Jurassic Jiulongshan Formation near Daohugou Village, Inner Mongolia, China. This is the first record of the genus Sphenarion (Czekanowskiales) from the Daohugou Biota and from China based upon the gross leaf morphology and the epidermal structures. The new species has 7–8 persistent, linear leaves clustered on a short shoot. The amphistomatic leaves, with distinctive stomatal and nonstomatal zones on both upper and lower epidermis are simple or mostly fork once. The new species provides new morphological and epidermal data and extends stratigraphic and geographic distribution of Sphenarion in Eurasia. Meanwhile, the new discovery is significant in understanding the floral composition, paleoclimate, and paleoenviroment of the Daohugou Biota. Analysis of the cuticular structures presented here and preliminary examination of other associated plant groups suggest that the new species grew in an area with a seasonal warm and humid climate in a warm-temperate zone.

Early harvest increases post-harvest physiological quality of Araucaria angustifolia (Araucariaceae) seeds.

Araucaria angustifolia is a conifer native to Brazil and is an endangered species. Since this species seeds have a short period of viability, its vulnerability is higher. Thus the aim of this study was to evaluate the physiological quality of A. angustifolia seeds during the development and post-storage periods. For this, cones of A. angustifolia were collected from a natural population in Curitibanos, Santa Catarina, Brazil, in March, April, May and June 2012. The collected seeds were classified into developmental stages of cotyledonary, I, II and III according to the month of collection; a total of 10 cones were collected for each stage. Seeds were stored in a refrigerator for 60 and 120 days, and were submitted to a chamber germination test (25 °C-photoperiod 12 h). Additionally, seeds were tested for moisture content (105 °C for 24 hours), tetrazolium (0.1 % for 1 hour) and vigor (electric conductivity [75 mL distilled water at 25 °C], germination speed index, and shoot and root length). Our results showed that during seed development, moisture content decreased from the cotyledonary stage (66.54 %) to stage III (49.69 %), and vigor increased in the last stage. During storage, moisture content at cotyledonary stage and stage I was stable. On the other hand, stored seeds exhibited a decrease in moisture content after 120 days at stages II and III. Physiological quality at the cotyledonary stage resulted in an increased germination rate of 86 % and 93 % after 60 and 120 days of storage, respectively; unlike stages II and III exhibited a decrease in seed viability and vigor after storage. Electrical conductivity was higher for fresh seeds at the cotyledonary stage, than for those stored for 60 and 120 days. However, in other stages, released leachate content after 120 days of storage, increased with the advance of the collection period. Germination speed index and shoot and root lengths after storage were highest for seeds at the cotyledonary stage and stage I; unlike stages II and III which had short root and shoot lengths during storage. Thus, the maintenance of seed moisture content during storage was variable and dependent on the period of collection. Furthermore, the physiological quality differed among earlier and later stages. Early collection favored seed physiological quality, and may be a strategy for better conservation of A. angustifolia seeds.

Phylogenetic diversification of Early Cretaceous seed plants: The compound seed cone of Doylea tetrahedrasperma

Discovery of cupulate ovules of Doylea tetrahedrasperma within a compact, compound seed cone highlights the rich diversity of fructification morphologies, pollination biologies, postpollination enclosure of seeds, and systematic diversity of Early Cretaceous gymnosperms. Specimens were studied using the cellulose acetate peel technique, three-dimensional reconstructions (in AVIZO), and morphological phylogenetic analyses (in TNT). Doylea tetrahedrasperma has bract/fertile short shoot complexes helically arranged within a compact, compound seed cone. Complexes diverge from the axis as a single unit and separate distally into a free bract tip and two sporophylls. Each sporophyll bears a single, abaxial seed, recurved toward the cone axis, that is enveloped after pollinaton by sporophyll tissue, forming a closed cupule. Ovules are pollinated by bisaccate grains captured by micropylar pollination horns. The unique combination of characters shown by D. tetrahedrasperma includes the presence of cupulate seeds borne in conifer-like compound seed cones, an ovuliferous scale analogue structurally equivalent to the ovulate stalk of Ginkgo biloba, gymnospermous pollination, and nearly complete enclosure of mature seeds. These features characterize the Doyleales ord. nov., clearly distinguish it from the seed fern order Corystospermales, and allow for recognition of another recently described Early Cretaceous seed plant as a second species in genus Doylea. A morphological phylogenetic analysis highlights systematic relationships of the Doyleales ord. nov. and emphasizes the explosive phylogenetic diversification of gymnosperms that was underway at the time when flowering plants may have originated and/or first began to radiate.

Canopy structure and light interception partitioning among shoots estimated from virtual trees: comparison between apple cultivars grown on different interstocks on the Chinese Loess Plateau

Dwarf interstock produced smaller tree size and a more uniform leaf area spatial distribution of vegetative short shoot. These improved light interception and increased light partitioning to fruiting shoot. The agronomic efficiency of dwarf interstocks is controversial in China, where almost 90 % of apple orchards, including high-density orchards, currently use vigorous rootstock. We quantified the influence of dwarf interstock on canopy structure and light interception in two apple cultivars commonly grown on the Chinese Loess Plateau. ‘Fuji’ and ‘Gala’ apple trees were grafted onto two rootstock/interstock combinations: M. micromalus/M. domestica cv. ‘Qinguan’, a vigorous interstock and M. micromalus/M26, a dwarf interstock. Nineteen trees, grown with the spindle training system, were digitized and allometric relationships were determined for all shoot types before harvests in 2011 and 2012. Virtual three-dimensional canopies were reconstructed and light interception was evaluated. The spatial distribution of leaf area density of vegetative short shoot was more uniform on dwarf interstock compared to the vigorous interstock. These improvements led to higher light interception efficiency in dwarf interstock trees. There were fewer poorly illuminated within-tree zones and shoots on dwarf interstock than on vigorous interstock. The dwarf interstock trees showed a 25 % silhouette to total leaf area (STAR) increase for the whole tree and 21 and 17 % STAR increases for fruiting shoots and vegetative short shoots, respectively. ‘Fuji’ foliage was more clumped than ‘Gala’, leading to lower light interception. The results indicate that dwarf interstocks can effectively improve light interception efficiency.

Comparative performance of warm season turfgrass varieties under Delhi conditions

The present investigation was carried out at Division of Floriculture and Landscaping, Indian Agricultural Research Institute, Pusa, New Delhi. The experiment was laid out in randomized block design (RBD) with three replications and seven treatments consisting of six varieties (viz. Selection 1, Bargusto, Panama, Panam, Palma and Tifdwarf 419) and Paspalum notatum species. These were evaluated for their suitability to be used as turfgrass under Delhi conditions. The suitability was evaluated on the basis of different morphological, physiological and biochemical traits. Out of evaluated varieties and species, Tifdwarf 419 exhibited better performance with respect to shoot dry weight (2.03 g/ 100 cm2), shoot fresh weight (5.78 g/100 cm2), root length (17.17 cm), root density (35.00 number/100 cm3), relative water content (86.96 %), chlorophyll a (2.63 mg/g fresh weight), chlorophyll b (0.53 mg/g fresh weight) and total chlorophyll (3.24 mg/g fresh weight) when compared to other varieties. Apart from these characteristics, short shoot length of 6.07 cm and high shoot density (331.27 number/100 cm2 area), along with good colour throughout the growing season was observed in Tifdwarf 419. Selection 1 also showed desirable shoot fresh weight (5.07 g/100 cm2), root length (16.10 cm), root density (28.87 number/100 cm3) and shoot density (395.40 number/100 cm2 area). The Cynodon dactylon varieties Tifdwarf 419 and Selection 1 were found to be most suitable to be used as turfgrasses in Delhi conditions.

Effects of experimental defoliation on resource allocation using integrated physiological units in the andromonoecious Camptotheca acuminata

The resource allocation of individual plants is a relatively complex process. Trade-off exists between vegetative growth and reproduction, male and female characteristics in monoecious plant. Camptotheca acuminata Decne. (Nyssaceae) is a perennial woody plant that annually forms short shoots that contain an apex cyme consisting of four to six capitula and four to eight (usually six) alternate leaves. We regard these short shoots as integrated physiological units (IPUs). Three levels of defoliation treatments were applied to the IPUs: 100%, 50% and 0% (control). The results showed that in the primary capitula the male input (pollen production) decreased and the change of female function (pistil weight) was not statistically significant. In contrast, the secondary capitula exhibited a plastic shift toward maleness and stopped producing pistils but increased pollen production. Due to the inherent inflorescence structures and flowering time sequence of the cymes, the effects of defoliating different capitulum positions were diverse, and the secondary and tertiary capitula suffered greater effects than those in the primary position. Moreover, the effects of 100% defoliation were more significant than those of 50% defoliation. Furthermore, no new leaves were produced within the IPUs after defoliation, but the photosynthetic capacities of the remaining leaves were enhanced. The results of this study revealed that defoliation on IPUs had different impacts on the reproductive and vegetative traits, and caused a trade-off between male and female functions in C. acuminata. These findings indicated that defoliation on IPUs can help to explain sex allocation in the andromonoecious C. acuminata, and resource limitations further intensify intra-inflorescense sex allocation.

The influence of water stress on grapevine (Vitis vinifera L.) shoots in a cool, humid climate: growth, gas exchange and hydraulics

Recent climatic trends of higher average temperatures and erratic precipitation patterns are resulting in decreased soil moisture availability and, consequently, periods of water stress. We studied the effects of seasonal water stress on grapevine (Vitis vinifera L. cv. Riesling grafted onto 101-14 (Vitis riparia Michx.×Vitis rupestris Scheele) rootstock) shoot growth, leaf gas exchange, xylem morphology and hydraulic performance in the cool-climate Finger Lakes region of New York. A plastic rain exclusion tarp was installed on the vineyard floor to create a soil moisture deficit and consequently induce vine water stress. Weekly measurements of predawn leaf and midday stem water potentials (Ψmd) were made, and two contrasting shoot length classes, long (length >2.0m) and short (length <1.0m), were monitored. Growth of both long and short shoots was positively correlated with Ψmd but no difference in water status was found between the two. Compared with rain-fed vines, water-stressed vines had lower photosynthesis and stomatal conductance later in the season when Ψmd dropped below -1.2MPa. Long shoots had three-fold higher xylem-specific hydraulic conductivity values than short shoots. Long shoots experiencing water stress were less vulnerable to xylem cavitation than shorter shoots even though they had more large-diameter vessels. The lower vulnerability to cavitation of long shoots may be attributed to less xylem intervessel pitting being found in long shoots, consistent with the air-seeding hypothesis, and suggests that a hydraulic advantage enables them to maintain superior growth and productivity under water stress.

Plastic Injection Quality Controlling Using the Lean Six Sigma and FMEA Method

PT. Yogya Presisi Teknikatama Industri (PT. YPTI) is a mold, precision part, and plastic injection maker company. One of the obstacles faced by the company is the high level of nonconformity on its production results. The waste on production process can be identified and classified into four types, i.e.: a). during the process of injection molding machines, b). finishing and cutting processes, c). quality control process and d). the packaging process. The objectives of this research are minimizing the defective goods and reducing the waste using Lean Six Sigma and FMEA approaches, especially for Bush product. From the analysis result, defective types on Bush product can be classified into bubble, speckle, short shoot, sunken, sink mark, over-cut, flashing, and discolor. Based on the attributes data on Bush product, the DPMO score is 988.42 or the sigma level is 4.6, While the DPMO score on the variable data on each dimension i.e.: a). Slit width on the bottom side has DPMO score of 30119 (sigma level 3.37), b). Diameter of the circle on the top side has DPMO score of 392294 (sigma level 1.77), c). Product thickness on the top side has DPMO score of 70474 (sigma level 2.97), d). Product height has DPMO score of 82107 (sigma level 2.89), product thickness on the bottom side has DPMO score of 24448 (sigma level 3.47), and f). Diameter of the circle on the bottom side has DPMO score of 24448 (sigma level 3.47). The highest RPN score on the dominant types of product defects which needs improvement are the defective goods of bubble type has RPN score of 729, flashing and the molten material out on the heating channel has RPN score of 384, over cutting has RPN score of 324 and sink mark has RPN score of 270. The recommendations for improvement that can be given from this research are making checklist for maintenance and production monitoring, enhancing work supervision and inspection, as well as improving the environment and work stations.

Influence of light-emitting diodes and benzylaminopurin on adventitious shoot regeneration of water hyssop (Bacopa monnieri (L.) pennell) in vitro

Water hyssop (Bacopa monnieri (L.) Pennell) is a medicinal plants. Its upper and lower halves of leaf explants were incubated in Murashige and Skoog (MS) medium supplemented with 0.25, 0.50 and 1.0 mg/L benzylaminopurine (BA) for 8 weeks; the explants were exposed to white (W) and red and blue (R and B, respectively) light-emitting diodes (LEDs), at 4:1, 3:1, 2:1 and 1:1 R and B light ratios, respectively. Shoot regeneration (100%) was achieved from all explants at all applied concentrations of BA and LED types. All explants showed different BA concentration requirements for regeneration of the maximum number of shoots. Longer shoots were obtained on medium with 0.25 mg/L BA. The W LED lighting system was found to be more effective for regenerating the maximum number of shoots (26.11) per explant (on the upper half of the leaf). Conversely, longer and shorter shoots were generated under 1:1 R:B and W LEDs, respectively. The number of shoots per explant ranged from 9.67-24.0 (full leaf), 6.33-25.92 (lower half of the leaf) and 7.33-27.33 (upper half of the leaf), respectively, in response to BA and LED light. Shoot length ranged from 0.94-1.90 cm (full lamina), 0.70-2.11 cm (lower half of the leaf) and 0.93-1.83 cm (upper half of the lamina) in response to BA and LED lifght. Regenerated shoots were successfully rooted using indole-3-butyric acid (IBA) and acclimatized in the aquarium provided with tap water.

Ginkgophytes of the Ul’ya flora (the Ul’ya depresiion, the Okhotsk-Chukotka volcanogenic belt)

The Ul’ya flora comes from the Coniacian volcanogenic deposits of the Amka Formation (the Ul'ya depression, southern part of the Okhotsk-Chukotka volcanogenic belt). Ginkgoaleans are diverse in this flora and represented by three genera: Ginkgo, Sphenobaiera and Baiera. All specimens have no cuticle and were assigned to morphotaxa. Genus Ginkgo includes two species: G. ex gr. adiantoides (Ung.) Heer with entire leaves and G. ex gr. sibirica Heer with dissected leaves. Genus Sphenobaiera also consists of two species: S. ex gr. longifolia (Pom.) Florin with 4–8 leaf lobes and S. ex gr. biloba Prynada with two leaf lobes. Genus Baiera is represented by new species B. lebedevii Golovn., sp. nov.Leaves of this species are 25–30 cm long and 13–16 cm wide, narrowly wedge-shaped with flat slender petiole, dichotomously dissected 4–5 times into linear segments 3–6 mm wide with 6–12 veins. The length of ultimate segments is equal to about a half of leaf length. Leaves attached spirally to ovoid short shoots about 2 cm long. Among the Late Cretaceous floras similar diversity of ginkgoaleans was recorded only in the Turonian-Coniacian Arman flora from middle part of the Okhotsk-Chukotka volcanogenic belt (Herman et al., 2016). Four species of ginkgoaleans from the Ul’ya flora (except G. ex gr. adiantoides) are considered as the Early Cretaceous relicts.

Effect of sand grain shape on root and shoot growth of wheat seedlings

Sandy soils are used in agriculture worldwide, and sandy material is a suitable growth medium in pot cultures. The global shape and surface roughness of sand grains affect inter-particle contact junctions and internal frictional resistance. Less rounded sands have greater inter-particle frictional resistance that may diminish the capability of roots to displace surrounding particles during growth. The aim of this study was to evaluate the effects of two silica sands of rounded (fluvioglacial) and rough (aeolian) origin on root and shoot growth of wheat seedlings. The greater shape irregularity of the rough compared to the rounded sand was shown by the circularity values and two surface structure parameters. Seedlings were grown for five days in 100cm3 steel cylinders filled with the respective sands with water content 0.20kgkg−1, corresponding to field water capacity. The rough sand compared to rounded had higher water permeability (P<0.05). Seedlings grown in rough compared to rounded sand were characterized by more tortuous root growth and significantly lower (P<0.05) root length (by 19.8%), root dry weight (by 15.9%) and greater root diameter (0.45 vs. 0.50mm). These root responses in rough sand were attributed to hindered displacement of the sand particles due to interlocking. The seedlings in rough sand had significantly (P<0.05) shorter shoots (by 9.8%), lower dry mass (by 11.7%) and leaf area (by 16.9%). These results imply the need to consider the effects of particle shape in sand-based growth media that are used in screening approaches to initial plant growth, particularly in plant genetics.

Competition from native hydrophytes reduces establishment and growth of invasive dense-flowered cordgrass (Spartina densiflora)

Experimental studies to determine the nature of ecological interactions between invasive and native species are necessary for conserving and restoring native species in impacted habitats. Theory predicts that species boundaries along environmental gradients are determined by physical factors in stressful environments and by competitive ability in benign environments, but little is known about the mechanisms by which hydrophytes exclude halophytes and the life history stage at which these mechanisms are able to operate. The ongoing invasion of the South American Spartina densiflora in European marshes is causing concern about potential impacts to native plants along the marsh salinity gradient, offering an opportunity to evaluate the mechanisms by which native hydrophytes may limit, or even prevent, the expansion of invasive halophytes. Our study compared S. densiflora seedling establishment with and without competition with Phragmites australis and Typha domingensis, two hydrophytes differing in clonal architecture. We hypothesized that seedlings of the stress tolerant S. densiflora would be out-competed by stands of P. australis and T. domingensis. Growth, survivorship, biomass patterns and foliar nutrient content were recorded in a common garden experiment to determine the effect of mature P. australis and T. domingensis on the growth and colonization of S. densiflora under fresh water conditions where invasion events are likely to occur. Mature P. australis stands prevented establishment of S. densiflora seedlings and T. domingensis reduced S. densiflora establishment by 38%. Seedlings grown with P. australis produced fewer than five short shoots and all plants died after ca. 2 yrs. Our results showed that direct competition, most likely for subterranean resources, was responsible for decreased growth rate and survivorship of S. densiflora. The presence of healthy stands of P. australis, and to some extent T. domingensis, along river channels and in brackish marshes may prevent the invasion of S. densiflora by stopping the establishment of its seedlings.

An Experiment In Breeding Cut Roses For The Indonesian Highlands

BIOBREES is a co-operative scientific programme between Indonesia and The Netherlands, of which the rose part aims at breeding cut roses adapted to the tropical highland. Within that scope four direct plant characters of 62 cut rose genotypes in different physiological stages were studied. The genotypes originated from cross-breeding in 1995 and successive selection for cut rose properties in populations at Plant Research International, Wageningen, The Netherlands, in 1996. Plant stages stuAn died were (i) superior adult seedlings in Wageningen in 1996, (ii) clones grafted onto Natal Briar both in Wageningen and Cipanas in 1997. Clonal Plant Research International, Wageningen, Plant Research International, Wageningen, clonal plants in Cipanas had significantly shorter shoots, more thorns, smaller flowers and fewer petals than the adult seedlings in Wageningen. Clonal plants in Wageningen, however, had significantly longer shoots; more thorns, and larger flowers with more petals than the seedlings in Wageningen. Despite differences in level of expression, for each character the absence of genotype-location interaction was ascertained. The expression of characters as influenced by light (both quantitative and qualitative), temperature and cultivation is discussed in relation to selection of cut roses in the temperate zone, which are adapted to the tropical highland.

INTERSPECIFIC HYBRID KIWIFRUIT ROOTSTOCKS HAVE POTENTIAL TO MODIFY SCION ARCHITECTURE AND VIGOUR OF YOUNG 'HAYWARD' VINES

Knowledge of how rootstocks affect scion architecture and vigour in kiwifruit is limited, unlike for some fruit crops. For example, in apple, scion dwarfing by ‘Malling 9’ (‘M9’) rootstock can be measured within the first two years following grafting. Architectural modifications imposed by ‘M9’ on the scion include early shoot termination and therefore less node neo-formation, and fewer sylleptic shoots. Currently in kiwifruit, there are no vigour-controlling rootstocks that reduce scion vigour in ways similar to those in apple. To elucidate the potential of Actinidia rootstocks on vigour control and altered scion architecture of kiwifruit, ‘Hayward’ scions grafted onto thirteen hybrid rootstocks were assessed at 8 and 14 months following grafting. Inter-specific hybrid rootstocks affected the early growth and altered initial shoot architecture of the ‘Hayward’ scion. For example, rootstocks modified the trunk cross-sectional area and proleptic budbreak of the ‘Hayward’ primary shoot. The lengths of long and short proleptic shoots of the scion from particular rootstocks were also slightly reduced, thus reducing the total length of proleptic shoots on grafted scions. Based on this promising evidence, selected Actinidia rootstocks show some potential to modify scion architecture and vigour during initial vine development. Vine architecture and components of yield will be further assessed in subsequent years as these vines mature.

Design and implementation of maximum constant boost switched inductor z-source inverter for three-phase on-line uninterrupted power supply

Purpose – The purpose of this paper is to present the Switched Inductor Z-Source Inverter (SLZSI) topology for three-phase on-line uninterruptible power supply (UPS) by employing third harmonic injected maximum constant boost pulse width modulation (PWM) control. Conventional UPS consists of step-up transformer or boost chopper along with voltage source inverter (VSI) which reduces the efficiency and increases energy conversion cost. The proposed three-phase UPS by using SLZSI has the voltage boost capability through shoot through zero state which is not available in traditional VSI and current source inverter. Design/methodology/approach – Performance of three-phase on-line UPS based on ZLZSI by using third harmonic injected maximum constant boost PWM control is analyzed and evaluated in MATLAB/Simulink software and the results are compared with Z-source inverter (ZSI) fed UPS. Experimental results are presented for the validation of the simulation and theoretical analysis. Findings – The output voltages, currents, THD values, voltage stress and efficiencies for different loading condition are determined and compared with the theoretical values and UPS with ZSI. The experimental results validate the theoretical and simulation results. Originality/value – Compared with the traditional ZSI, the SLZSI provides high-voltage boost inversion ability with a very short shoot through zero state. This proposed UPS by using SLZSI increases the efficiency with less number of components, reduces the harmonics, increases the voltage gain and reduces the voltage stress.

The comparison of dormancy dynamics in apple trees grown under temperate and mild winter climates imposes a renewal of classical approaches

This study is an important contribution to understanding of the dormancy dynamics of apple buds grown in contrasting climates, highlighting the main factors possibly involved in their control and the key role of rehydration. The aim of this study was to compare the dormancy dynamics and the physiological status of vegetative and floral buds of apple cultivars grown during cold and mild winters. Long shoots bearing vegetative buds and short shoots bearing floral buds were regularly collected during two successive cycles at Marsillargues, France (2011/12, 2012/13) and Palmas, Parana, Brazil (2012, 2013). The dormant state in vegetative buds was evaluated by the single-node cutting test and in floral buds by the Tabuenca’s test. The first approach highlighted important differences in the dormancy dynamics in both sites, clearly showing that: (1) the entry and the maximum level of dormancy are strongly correlated with cold winter temperatures; (2) the three classical phases of dormancy dynamics are difficult to differentiate under a mild winter climate; and (3) endodormancy, if it actually exists, is very weak and lasts only for a short time. Distinct temporal changes between both sites were found for flower primordia fresh and dry weight. The ecodormant state was linked to significant changes in dry weight and the capacity to quickly reach a water content of around 77 % according to the Tabuenca’s test. High temperatures in Brazil allowed a quick transition between endodormancy and ecodormancy compared to France where the rehydration period was long. The weak endodormancy associated with a quasi-absence of ecodormancy could explain the strong spatio-temporal heterogeneity of budburst and flowering under a mild winter climate. This may be useful for understanding the future phenology of trees under global warming conditions and for the selection of adapted cultivars.

The annual biological cycles of Teucrium polium L. and Thymus sibthorpii Bentham (Lamiaceae)

Teucrium polium appears in winter as a cluster of short shoots with small leaves (chamaephyte). In early spring, shoots progressively elongate until in late spring shoot elongation ceases. At the tip of each shoot, an inflorescence (dichasium with apical racemes) is developed which completes pollination by the end of July. Summer leaves are about 10-fold larger than winter leaves. In November, summer leaves are shed and the leaf-naked shoots later become dried and abscise. In winter, the dormant buds at the base of the plant break dormancy and generate many short shoots forming a claster.Thymus sibthorpii is also chamaephyte. In early spring, the short winter shoots start increasing in length and by the end of April shoot elongation becomes completed. On the tip of each shoot an inflorescence (raceme) is developed which completes pollination by the end of May. In summer, plants consist of leaf-bearing shoots only (inflorescence axes dry and then drop down). In November, all leaves are shed and small shoots sprout out from dormant buds at the base of the plant.