Number Of Lateral Shoots Research Articles

Charophytes collapse beyond a critical warming and brownification threshold in shallow lake systems

Charophytes play a critical role for the functioning of shallow lake ecosystems. Although growth of charophytes can be limited by many factors, such as temperature, nutrients and light availability, our understanding about concomitant effects of climate warming and other large-scale environmental perturbations, e.g. increases in humic matter content (‘brownification’) is still limited. Here we conducted an outdoor mesocosm experiment during 71days with a common charophyte species, Chara vulgaris, along an increasing gradient of temperature and brownification. We hypothesized the growth of C. vulgaris to increase with temperature, but to level off along the combined temperature and brownification gradient when reaching a critical threshold for light limitation via brownification. We show that C. vulgaris increases the relative growth rate (RGR), main and total shoot elongation, as well as number of lateral shoots when temperature and brownification increased by +2°C and+100%, respectively above today's levels. However, the RGR, shoot elongation and number of lateral shoots declined at further increment of temperature and brownification. Macrophyte weight-length ratio decreased with increased temperature and brownification, indicating that C. vulgaris allocate more resources or energy for shoot elongation instead of biomass increase at warmer temperatures and higher brownification. Our study shows that C. vulgaris will initially benefit from warming and brownification but will then decline as a future scenario of increased warming and brownification reaches a certain threshold level, in case of our experiment at +4°C and a 2-fold increase in brownification above today's levels.

Tolerance of hazelnuts towards unfavorable environmental factors

Tolerance of hazelnuts towards unfavorable environmental factors

The combined effect of green-waste compost and fertilization on growth ofFicus benjamina

The most widespread, internationally, organic substrate material for growing ornamental plants is peat. Peat however is imported in most countries and it is an expensive material. In addition, it is considered a non-renewable natural resource and its intensive extraction has negative environmental impacts. Therefore, even the partial replacement of peat in the substrate of ornamentals by other cheap and organic materials available in large quantities is required. In this study, the effect of green-waste compost (GWC) combined or not with fertilization on growth of Ficus benjamina was studied, in order to evaluate the possibility of replacing part of the peat of the substrate with this compost. Rooted cuttings were cultured for 10 months on peat-perlite (1:1 v/v, control substrate) and on three other substrates, where 25, 50 or 75% of peat (by volume) was replaced by GMC. Half of the plants in each substrate were fertilized weekly with a complete water soluble fertilizer (20:20:20). Plant growth was evaluated at the end of the experiment recording plant height, thickness of the main stem, number and length of lateral shoots, as well as dry weight of the above-ground and the root biomass. GMC promoted growth of the non-fertilized plants, but it could not replace fertilization, since only in two of the growth assessment parameters, that of the main stem thickness and the dry weight of the roots, the replacement of peat by GMC at 50 or 75% without fertilization induced similar values with the fertilized control. When fertilization was applied, the GWC successfully replaced peat at even 75% yielding quite satisfactory plant growth similar to that of the control.

Reproductive biology of Cornus capitata Wall. ex Roxb.: a native species in East Asia

The reproductive biology of Cornus capitata was studied in detail from June 2014 to October 2015 in Tehri Garhwal, Uttarakhand, western Himalaya, India and elucidated floral morphology, confirming autogamy, geitonogamy, and xenogamy. A new inflorescence ball formed each year with developing fruits that were initiated the previous year; thus reproduction is a continuous cycle. The total pollen production within a tree ranged between 4.0 × 107 and 9.3 × 107. Anthesis peaked between 08:00 and 10:00. There was significant effect of micro-environmental condition on anthesis (F = 243.8, p = 3.01). A significant positive relationship between the number of lateral shoots and total inflorescence showed that the inflorescence production in C. capitate depends largely on the number of lateral shoots. Time and concentration of various solutions significantly affected pollen germination (time: F = 5.39, p = 0.002; concentration: F = 1.40, p = 0.234). Anthophora bees and thrips were observed as the main pollinators. There was a significant difference in seed set between natural and obligate self-pollination (t = 11.84, p = 1.99). Significant effect was also observed on fruit size (t = 8.88, p = 2.09) between open and shaded conditions. SEM micrographs of pollen grains showed that the shape of dehydrated pollen grains differed greatly due to variations in the rate of dehydration among pollen grains within the anther. Seed germination was observed only in quality seed derived from open pollination, supporting xenogamy in C. capitata. Findings of the present study will be of immense value in formulating effective conservation measures for the species in wild habitats.

Wpływ zabiegów stymulujących rozgałęzianie na jakość okulantów jabłoni

The objective of the paper was to study the impact of mechanical and chemical treatments stimulating branching on the quality of ‘Gloster’ and ‘Jonagold’ apple tree maidens budded onto the M.9 rootstock. The studies showed that the height of the assessed apple tree maidens was dependent on a cultivar in most combinations and hence, the ‘Gloster’ apple tree maidens were significantly shorter than ‘Jonagold’ cultivar during the intensive growth period in summer. In autumn, on the other hand, an inverse relationship was noted. Throughout the entire vegetative season, no significant influence of the applied treatments was found on height increments, stem diameter of rootstocks and maiden trees or the sum of lateral shoot length of the apple trees under investigation. The Globaryll 100 SL preparation applied three times on ‘Jonagold’ cultivar plants significantly increased the numbers of sylleptic shoots compared to the other combinations. In most combinations, the number of lateral shoots depended significantly on a cultivar.

Growth and quality of cucumber, tomato, and green bean under foliar and soil applications of an aminochelate fertilizer

Aminochelates are relatively new fertilizer formulations with improved efficiency for agricultural applications. Many plant responses to these amino acid-based fertilizers have not yet been well studied. In the present study, we evaluated the effects of soil (six split applications at a final volume of 5 mL) and foliar application (six applications at 0.2% concentration) of a commercial aminochelate (liquid fertilizer consisting of 2.0% N-amino acid, 2.5% Zn, 2.0% Fe, 1.5% Mn and 0.4% Cu) on growth, yield, and quality traits in three vegetable crops including tomato (Solanum lycopersicum), cucumber (Cucumis sativus), and green bean (Phaseolus vulgaris) under field conditions in lime soil. Plant growth, yield, and quality parameters significantly increased in response to foliar application, and to lesser extent soil application of aminochelate fertilizer. Plants treated with foliar application of aminochelate had a significantly higher chlorophyll index, number of lateral shoots, shoot dry weight, number of fruits, plant yield, and leaf N concentration in all three vegetable crops compared to the control. Soil application of aminochelate resulted in significantly higher fruit or pod vitamin C content and total soluble solids content versus the control. However, for most traits, there was no significant difference between soil application of aminochelate versus chemical fertilizer a (N, P, K mixture). Nevertheless, the results indicate that the application of aminochelate especially foliar application, is a preferred method for fertilization under lime soil conditions to improve plant growth, productivity, and quality.

Blackberry and raspberry seedlings growth under the soilless cultivation system

The objective of this study was to evaluate the growth of micropropagated blueberry and raspberry seedlings under conventional and soilless cultivation systems. Seedlings of two blackberry cultivars (Xavante and Tupy) and two raspberry cultivars (Heritage and Fall Gold) were submitted to two cultivation systems: the conventional system and the soilless system. Under the conventional system, they were kept in polyethylene bags containing H. Decker® substrate and were irrigated with nutritive solution every 15 days. Under the soilless system, they remained in plastic flowerpots containing sand and were irrigated with nutritive solution daily. In regards to shoot length, the Xavante, Tupy, Heritage and Fall Gold cultivars showed the best results under the soilless cultivation system. As for number of lateral shoots, the Xavante, Heritage and Gold Fall showed significant results under the soilless system, unlike the cultivar Tupy, which showed better results under the conventional system. The soilless cultivation system is suitable for the development of the blackberry 'Xavante' and 'Tupy' and the raspberry 'Heritage' and 'Fall Gold' mini-cuttings

Tomato plant growth, leaf nutrient concentrations and fruit quality under nitrogen foliar applications

Tomato is a typical plant that has distinct response to different nitrogen forms in hydroponic culture. In addition, it is a well known susceptible plant to ammonium nutrition in hydroponic culture. However, its response to foliar application of nitrogen sources and N-forms has not been well investigated. In the present study, the growth, productivity and fruit quality of tomato was investigated under foliar application of nitrogen from different sources. Ammonium sulfate, urea and calcium nitrate with constant concentration of 100 mM N were weekly sprayed during four months under hydroponic culture system. A water spray treatment was considered as control. The results showed that vegetative growth parameters were significantly affected by N sources in different patterns. The factors such as plant height, leaf area, number of lateral shoots and shoot fresh and dry weight, as well as leaf nitrate reductase activity was significantly reduced by foliar application of ammonium sulfate and to less extent by urea, while there was improvement of these traits by foliar application of calcium nitrate compared to control. However, ammonium sulfate treated plants had the highest leaf SPAD value and leaf N concentrations. Plant fruiting pattern was also influenced by treatments, as ammonium sulfate spray reduced the fruit yield, and fruit vitamin C content, while it increased fruit TSS and titratable acidity. The highest value of yield and vitamin C was recorded in calcium nitrate sprayed plants.

Anatomical and morphological changes in scion of some olive grafting combinations under water deficit

Effects of water stress deficit were studied on xylem anatomical fea- tures and some growth parameters among six olive grafting combinations; Amygdalifolia/Arbequina (Am/Ar), Amygdalifolia/Koroneiki (Am/Ko), Amygdalifolia/Zard (Am/Z), Conservallia/Koroneiki (Co/Ko), Conservallia/Zard (Co/Z) and Conservallia/Arbequina (Co/Ar) of about three-year-old olive trees ( Olea europaea L.) under greenhouse conditions. To realize this, a factorial experiment was conducted in a completely randomized design (CRD). The results showed that rootstocks exhibited significant effects on scions xylem anatomical physiognomies, such as vessel lumen area (VLA) and vessel diame- ter (VD) and additionally on some growth indices including main stem length (SL), lateral shoot number (LSN) and graft union-cross sectional area (GU-CSA). Xylem anatomical characteristics including VLA, porosity, vessel frequency (VF) and VD of scions decreased when they were grafted onto Arbequina and Koroneiki rootstocks, but increased onto Zard rootstock. All growth parameters showed a decrease under drought stress, while this reduction was more pro- nounced for Zard rootstock than the other rootstocks. However, Co/Z showed the highest VF and the lowest vulnerability index (VI) and exhibited a better performance at the end of recovery.

Optimation of In vitro Lateral Shoots Multiplication of Papaya (Carica papaya L.) “Callina” with BAP and NAA

Papaya is a popular fruit and is grown commercially in many subtropical and tropical countries. Papayas are generally grown from seeds; therefore the offsprings are not true-to-type and could come in three sexes, female, male, and hermaphrodite. Clonal propagation is required to obtain to grow true-to-type hermaphrodite papayas. In this research, we developed an in vitro protocol for shoot multiplication from lateral shoots from in vitro germinated papaya seedlings. The in vitro propagated plant materials could potentially be used as a source of papaya micro cuttings, or as scion for papaya grafting. The experiment was set up as a factorial experiment with NAA at 0, 0.1 and 0.5 mg.L-1, and BAP at 0, 0.1, 0.5, and 1.0 mg.L-1 in a completely randomized block design. BAP interacted with NAA in affecting the shoot production per explant. The optimum BAP and NAA concentration to produce lateral shoots was 0.54 mg. L-1 and 0.1 mg.L-1, respectively. Media without NAA reduced the number of lateral shoots and number of leaf per explant at any BAP concentration.Keywords: hermaphrodite, seeds, true to type, clonal propagation, micro cuttings.

Enhancements in sucrose biosynthesis capacity affect shoot branching in Arabidopsis.

We previously demonstrated that transgenic tobacco plants expressing cyanobacterial fructose-1,6-/sedoheptulose-1,7-bisphosphatase in the cytosol increased the number of lateral shoots and leaves at elevated CO2 levels. These findings suggest that alterations in carbon partitioning affect the development of shoot branching. In order to elucidate the underlying mechanisms at the molecular level, we generated transgenic Arabidopsis plants overexpressing cyanobacterial fructose-1,6-bisphosphatase-II in the cytosol (AcF). At elevated CO2 levels, the number of lateral shoots was significantly increased in AcF plants. Sucrose and hexose levels were also higher in AcF plants than in wild-type plants. The expression levels of MAX1, MAX4, YUCCA8, YUCCA9, and BRC1, which are involved in auxin or strigolactone biosynthesis and responses, were lower in AcF plants than in wild-type plants. These results suggest that alterations in sugar partitioning affect hormone metabolism and responses, resulting in enhanced shoot branching.

The giant columnar cactus Pachycereus pringlei adaptively modifies its stem shape from the dry tropics into the arid mid-latitude deserts

Because of the lack of leaves, the distributions of columnar cacti are limited by their capacity to trade off their photosynthetic chlorenchyma and their non-photosynthetic storage parenchyma. For species with wide latitudinal ranges, variations in stem surface area:volume ratios could play an adaptive role. Based on the fact that Pachycereus pringlei spans more than a 1000 km along the Baja California Peninsula, we used this species to analyze changes in stem allometry between populations. We selected six sites, from latitude 23°–31° N, ranging from 518 to 55 mm of annual rainfall. We used an allometric model to analyze the diameter-to-height relationship, estimating the parameters through linear modeling. The height of the main stem when the first branch emerges was estimated by regressing the height of the plant against the number of lateral shoots. The solar radiation intercepted by an unbranched 6-m-tall cardon was estimated using an irradiance model. The diameter of adult plants, the stem height when cardons begin to branch, and the surface area:volume ratio, were all associated to latitude and to latitude-related environmental variables such as rainfall. For any given height, the surface area:volume ratio decreases from the wetter tropics into the arid mid-latitude deserts.

Synflorescence morphology of grasses with reduced terminal inflorescences: a case study of Jouvea (Cynodonteae, Chloridoideae, Poaceae)

Jouvea is a dioecious genus of grasses with two species. Molecular phylogenetic analyses place it in tribe Cynodonteae, closely related to subtribes Hilariinae and Scleropogoninae, and the genera Allolepis and Sohnsia. The staminate inflorescence in Jouvea is an ordinary grass spike of spikelets, but the pistillate inflorescence is represented by a single spikelet which lacks glumes, has a thick and cylindrical rachilla, lemmas forming a tube that enclose the palea and pistil, stigmas protruding from an apical pore of this tube, and does not have lodicules. Within Cynodonteae, inflorescences reduced to a single spikelet also occur in subtribe Monanthochloinae, in which the small number of flowers of the terminal inflorescence is compensated by an increase in the number of lateral floriferous shoots. We here describe the floriferous shoot system (synflorescence) of Jouvea and compare it to other cynodonteae grasses with reduced inflorescences. Jouvea species display a high number of lateral shoots (trophotagma enrichment axes) growing from the medial and distal zones of the synflorescences. These shoots have prophyllar origins and form clusters of lateral inflorescences. The elevated number of trophotagma enrichment axes of Jouvea may be associated with the extreme reduction in the pistillate terminal inflorescence. In addition, the increase in number of spikelets by the development of prophyllar branches is a unique strategy within tribe Cynodonteae.

Evaluation of Growth and Yield of Purple Coneflower (Echinacea purpurea L.) in Response to Biological and Chemical Fertilizers

In order to study the effects of biological and chemical fertilizers on quantitative and qualitative yields of purple coneflower, an experiment was carried out during 2010-2012. The morphological traits such as plant height, number of lateral shoots, shoot fresh and dry weight, root fresh and dry weight, number of inflorescences per plant, number of flower buds per plant, and essential oil content and yield were measured. The results showed significant effects of the treatments on the growth parameters. In the second year, the mixture of the three bacteria plus mycorrhizal inoculum improved important parameters such as shoot dry weight (40.42%), root dry weight (60.02%), and number of inflorescences per plant (65.68%). Interestingly, these values were not significantly different from obtained results by the chemical fertilizers. Additionally, the essential oil content in plants treated with the mixture of the three bacteria were 152.14% and 25.11% higher than the control plants in the first and the second year, respectively. The essential oil yield in plants treated with the mixture of the three bacteria was higher than those treated with the chemical fertilizers in two years. The results indicate that using biological fertilizers is a good choice to reduce the use of chemical fertilizers as an important tool to contribute to a sustainable agriculture.

Effect of Iron, KNO3, GA3 and Humic acid on Growth and Leaf Nutrients of Almond (Prunus amygdalus L.) Transplants 1-Vegetative Growth

This investigation was conducted during the growing season of 2011-2012, in the nursery of the Malta station/ Duhok. Kurdistan region, Iraq. On two year old Almond transplants, grown in polyethylene bags. The transplants were foliar sprayed two times; 20th April , 10th May 2011, with three levels of Iron (0, 40, 80 mg.l-1), three levels of GA3 (0, 250 and 500 mg.l-1), four levels of KNO3 (0, 50,100, and 200 mg.l-1) and three levels of Humic acid (0, 25 and 50 mg.l-1). The transplants were left under nursery conditions till 1 October, 2011. The experimental was arranged as Factorial including Randomized Complete Block Design (R.C.B.D) with five replicates with five transplants per unit. Foliar spray of Humic acid at 50mg.l-1 increased significantly stem diameter (0.57 cm, lateral shoot length (25.33 cm), lateral shoot number (20.67), leaves number (62.67), leaves fresh (6.30%) and dry weight (3.33%). GA3 at 250 mg.l-1significantly increased leaves area (12.56 cm2), shoot fresh weight (25.4%), and dry weight (15.22%) and root length (38cm). However, 40mgFe.l-1 increases significantly chlorophyll content (66.63%). While, KNO3 significantly affected on root fresh weight (13.16 %), and dry weight (7.62%).

Morphology and Hydraulic Architecture of Vitis vinifera L. cv. Syrah and Torrontés Riojano Plants Are Unaffected by Variations in Red to Far-Red Ratio.

Plants have evolved an array of specific photoreceptors to acclimate to the light environment. By sensing light signals, photoreceptors modulate plant morphology, carbon- and water-physiology, crop yield and quality of harvestable organs, among other responses. Many cultural practices and crop management decisions alter light quantity and quality perceived by plants cultivated in the field. Under full sunlight, phytochromes perceive high red to far red ratios (R:FR; 1.1), whereas overhead or lateral low R:FR (below 1.1) are sensed in the presence of plant shade or neighboring plants, respectively. Grapevine is one of the most important fruit crops in the world. To date, studies on grapevine response to light focused on different Photosynthetic Active Radiation (PAR) levels; however, limited data exist about its response to light quality. In this study we aimed to investigate morphological, biochemical, and hydraulic responses of Vitis vinifera to variations in R:FR. Therefore, we irradiated Syrah and Torrontés Riojano plants, grown in a glasshouse, with lateral FR light (low lateral R:FR treatment), while others, that were kept as controls, were not irradiated (ambient lateral R:FR treatment). In response to the low lateral R:FR treatment, grapevine plants did not display any of the SAS morphological markers (i.e. stem length, petiole length and angle, number of lateral shoots) in any of the cultivars assessed, despite an increase in gibberelins and auxin concentrations in leaf tissues. Low lateral R:FR did not affect dry matter partitioning, water-related traits (stomata density and index, wood anatomy), or water-related physiology (plant conductance, transpiration rate, stem hydraulic conductivity, stomatal conductance). None of the Vitis vinifera varieties assessed displayed the classical morphological and hydraulic responses associated to SAS induced by phytochromes. We discuss these results in the context of natural grapevine environment and agronomical relevance.

The influence of elevated CO2 on the photosynthesis, carbohydrate status, and plastochron of young peach (Prunuspersica) trees

The plastochron, defined as the time interval between the initiations of two successive leaves, can also indicate the development of successive phytomers along a shoot. Previous work has shown that crop load impacts the plastochron in field-grown peach (Prunuspersica) trees, which led us to hypothesize that the plastochron of peach trees may be sensitive to the carbon status of the tree. To testthis hypothesis, a 38-day growth chamber study was conducted to determine if elevated CO2 (800 μmol·mol-1) speeds up the plastochron of young peach trees relative to their growth in ambient (400 μmol·mol-1) CO2. The leaf lamina lengths were measured every other day to generate leaf growth rate curves that were fitted against a classic Gompertz growth curve to estimate the time of the initiation of each leaf, which in turn, was used to estimate the plastochron. Additionally, in order to non-destructively gauge the effects of CO2 concentration on plant performance during the experiment, net leaf CO2 assimilation and stomatal conductance measurements were taken approximately half way through and at the end of the 38-day experiment. Doubling the ambient CO2 concentration had no effect on the plastochron, even though the leaf CO2 assimilation rates, leaf starch and total nonstructural carbohydrate concentrations were greater in trees grown in elevated CO2. In addition, there were no significant treatment differences in incremental shoot growth or the number of lateral syleptic shoots.

Exogenous Applications of Moringa Leaf Extract and Cytokinins Improve Plant Growth, Yield, and Fruit Quality of Cherry Tomato

Growth-promoting properties of moringa (Moringa oleifera) leaves were investigated for potential use in crop production by comparing the efficacy of bimonthly foliar and root applications of a moringa leaf extract [MLE (3.3% w/v)] with the cytokinins 6-benzyladenine (6-BA) and trans-zeatin (t-Z), each at 25 mg·L−1, to increase plant growth, flowering, yield, fruit size, and fruit quality of ‘Super Sweet 100’ cherry tomato (Solanum lycopersicum). Foliar-applied t-Z and root-applied MLE increased canopy biomass (P ≤ 0.01) and root- and foliar-applied MLE increased lateral vegetative shoot number (P ≤ 0.001) and plant height (P ≤ 0.001) relative to untreated control plants. Only foliar-applied MLE increased floral shoot number compared with untreated control plants (P ≤ 0.001). Plants in all treatments, except root-applied 6-BA, produced more flowers than untreated control plants (P ≤ 0.001). Plants receiving root-applied t-Z produced the greatest number of flowers followed by plants receiving root-applied MLE. Cherry tomato plants treated with root-applied t-Z or MLE produced the greatest number of fruit per plant and significantly more than untreated control plants (P ≤ 0.001). Foliar-applied 6-BA and MLE and root-applied t-Z and MLE increased yield as grams of fruit per plant compared with the untreated control (P ≤ 0.01). Foliar- and root-applied MLE increased fruit concentrations of soluble sugars (P ≤ 0.001), protein (P ≤ 0.001), antioxidants (P ≤ 0.001), and lycopene (P ≤ 0.001) compared with fruit from untreated control plants. Foliar- and/or root-applied MLE resulted in the greatest leaf concentrations of protein (P ≤ 0.01), proline (P ≤ 0.01), arginine (P ≤ 0.01), and total antioxidants (P ≤ 0.05), which were all significantly greater than the concentrations in leaves from untreated control plants. The results of this single experiment provide evidence suggesting that MLE warrants further research as an inexpensive growth promoter for enhancing tomato plant biomass, yield, and fruit quality, especially in organic crop production, which prohibits the use of many commercial synthetic plant growth regulators.

The impact of the period of sowing and fertilization on morphological characteristics and seed yield of garden poppy (Papaver somniferum L.)

Garden poppy (Papaver somniferum L.) is a traditional crop that had already been cultivated in Slovenia in the past for the production of seed and oil. During its re-introduction in present time, numerous agro-technical dilemmas have been raised for the processes from sowing to harvesting and have to be studied in our present growing conditions. On the fields of the Ograjšek farm in Cerklje ob Krki two field experiments in complete randomized design had been sown in 2013 and 2014 to establish the influence of the sowing date and fertilization on morphological properties and crop yield of garden poppy seed of the Austrian variety 'Zeno 2002'. Results have shown that the average yield of seed in both trials (1643 kg/ha) is more than one time higher than the average crop yield recorded globally (700 kg/ha), proving how suitable growing conditions in the area of eastern Dolenjska are for the cultivation of poppy. Analysis of crop yield per plot showed there is no statistically significant interaction between the considered factors. The yield of poppy seed in the spring sowing term was 1742±77 kg/ha and in the autumn sowing was 1545±122 kg/ha. The difference is not statistically significant (p = 0.1845). Recorded yield per plant was higher for the autumn term but that was not transferred to the total crop yield due to poor overwintering and consequentially lower plant density at the time of harvest. Both sowing dates have confirmed that exposure to light and duration of growing period had an important impact on plants height – average height of plants sown in autumn was 139±1 cm, which is more than 60 cm higher than the average height of the plants sown in spring (p = 0.0000). A strong statistical dependence of the yield of seed per capsule on diameter of the capsule was proved (p = 0.0000). It can be concluded that when the capsule diameter increases by 10 mm, the seed yield increases for 2.1 g to 2.3 g with 95 % confidence. Dependence of the average seed yield on the number of lateral shoots per plant also proved to be statistically significant (p = 0.0000). Linear model was used for the comparison of the four lines showed that the lines representing poppy sown in autumn and spring are statistically different for the control and for the ENTEC; the slope was higher for the poppy sown in autumn. These trials have given the first practical advice for production of garden poppy in Slovenia and should be continued for further useful results.

Salt and osmotic stress tolerances of the C3–C4 xero-halophyte Bassia sedoides from two populations differ in productivity and genetic polymorphism

The morphological, biochemical and genetic characteristics of two Bassia sedoides (Chenopodiaceae) populations in the Southern Urals were studied. The plants of the Makan and Podolsk populations differ in growth (approximately 10-fold), in water and potassium contents and Na+/K+ ratio. On the basis of the genetic assay (by isozymes, RAPD and ISSR markers) of B. sedoides from the Makan and Podolsk populations, the intraspecific differences have been identified. The more productive Makan population showed greater genetic polymorphism, whereas the less productive Podolsk population showed less genetic polymorphism. The seedlings of B. sedoides from the Makan and Podolsk populations were cultivated under low and moderate salinity (100 and 200 mM NaCl, respectively) and equivalent osmoticity generated by the two PEG concentrations. Both populations were sensitive to dehydration initiated by PEG. Podolsk seedlings were more sensitive to osmotic stress and were characterised by an increase in proline content. Low salinity (100 mM NaCl) was necessary for optimal growth of seedlings from the Makan population. They showed significantly increased fresh biomass and number of lateral shoots. The maximal growth of seedlings from Podolsk was under 0–100 mM NaCl, and their biomass was approximately 1.4-fold lower than that of the Makan seedlings. Under moderate salinity (200 mM NaCl), the Makan seedlings were more salt tolerant than the Podolsk seedlings because of maintaining a low Na+/K+ ratio. Under natural conditions, the excess of Na+/K+ ratio compared with values for optimal growth under laboratory conditions was approximately threefold for the Makan plants and approximately fivefold for the Podolsk plants. High values of the Na+/K+ ratio under natural conditions indicate a deficit of potassium in the soil. Perhaps, the degree of potassium deficiency is one of the factors influencing the differences in productivity and the level of genetic variation of B. sedoides under natural conditions.