RELATIONSHIP BETWEEN FLORAL MORPHOLOGY, FRUIT SETTING BEHAVIOR AND FINAL YIELD IN SOME EGGPLANT (Solanum melongena) GENOTYPES FROM IRAN

Heterostyly in eggplant flowers is a common trait that may affect the fruit production. The objective of this study was to evaluate the impact of heterostyly on fruit setting and yield of 13 eggplant genotypes from Iran. Flowers capable of setting fruit, including long- (LGs) and medium-styled flowers (MEs), accounted for the largest number of flowers (43.60-75.62%), while total short-styled flowers (SRTs) constituted a smaller percentage (20.47-45.51%) in different genotypes. However, SRTs represented a considerable proportion of the total number of eggplant flowers. Different eggplant genotypes produced 42.59-77.25% fruits from LGs+MEs, and only 0.0-3.77% from SRTs. In general, although the percentage of fruit setting of LGs and MEs was much greater compared to values of SRTs, there was no significant correlation between final yield and style length. Therefore, in order to increase eggplant yield, protecting fruits formed from LGs and MEs might be more effective than increasing the proportion of LGs and MEs to SRTs

EVALUATION OF THREE WILD SPECIES OF ALMOND ON THE BASIS OF THEIR MORPHOLOGICAL CHARACTERS

Due to the suitable climatic conditions, Iran is one of the most important growing centre for wild and domesticated species/varieties of almond. Because of the adaptability of wild almond species to severe environmental conditions and resistance to drought, salinity and some pest and diseases, these can be used as rootstock for almond cultivars and in breeding programs for rootstock improvement in Iran. In this study, seeds of Amygdalous scoparia, A.webbii and A. orientalis were planted. The analysis of variance showed a significant difference between species. However, A. scoparia had highest stem height and leaf length. At the end of the experiment, the thickest stems were developed by A. scoparia, whereas the thinnest stems by A. orientalis. A. webbii produced more number and longer roots per seedling than the other two species. The correlation between various morphological traits showed that a few shoot characters were significantly correlated with root traits. However, leaf length, leaf width, leaf area, root number and root diameter for P. webbii, and leaf number, leaf length, leaf width, petiole length and root number characters for P.scoparia, and stem height, leaf number, leaf length, petiole length, internode length and root number for P. orientalis were found to be important morphological traits to evaluate seedling charactristics of wild almond genotypes before their nursery test

Effect of plant growth regulators on two different types of eggplant flowers regarding style length and fruit setting

Aim of study: (i) to explore differences between eggplant flowers capable of setting fruit including long (LGs) and medium style flowers (MEs) and those which suffer from severe problems with fertility and fruit setting including short style ones (SRTs); (ii) to study the effect of plant growth regulators on floral morphology and fruit setting. Area of study: Isfahan University of Technology, Isfahan, Iran, 2017 and 2018. Material and methods: First the floral morphology and initial fruit setting of 13 eggplant genotypes from Iran were investigated. Then the differences between LGs and SRTs of two genotypes were explored. Finally, the effect of 1-naphthaleneacetic acid (NAA) and spermidine (Spd) on floral morphology and initial and final fruit setting of these two genotypes was determined. Main results: Results showed SRTs were not capable of fruit setting. Compared to SRTs, LGs had larger central canals, higher protein, total sugar, reducing sugar and K concentrations, as well as longer polar axis and pollen tubes and greater pollen viability. Although 1.5 mM Spd and 20 mg L-1 NAA resulted in increasing of LGs and MEs, and also total initial fruit set, surprisingly, no significant differences were observed in the final yield and final fruit set between the control and these treatments. Researching highlights: Since the rate of fruit dropping was higher in those treatments compared to the control, plants with more SRTs likely regulate their final load by abscising their flowers, and plants with more LGs regulate them by abscising their fruits

Influence of salicylic acid on morphological and physiological responses of banana (Musa acuminata cv. 'Berangan', AAA) shoot tips to in vitro water stress induced by polyethylene glycol

Abstract Growth and productivity of banana is seriously restricted by water deficit. Salicylic acid (SA) induces biotic and abiotic stress tolerance in crops. To study the ameliorative effects of SA on water stress in banana (Musa acuminata cv. 'Berangan', AAA), shoot tip explants with 8 mm in size were treated with varying SA concentrations (0, 1, 2 and 3 mM) and incubated on MS media containing different levels (0, 1, 2 and 3 %) of PEG in vitro. After 2 months, proliferation rate, fresh weight increase, relative water content, chlorophyll level, proline accumulation, malondialdehyde (MDA) and H 2 O 2 contents were measured and analyzed. The results indicated that with increasing levels of PEG, proliferation rate, fresh weight increase, relative water content and chlorophyll concentrations were significantly decreased. The SA concentrations improved shoot tips performance by increasing proliferation rate, fresh weight increase and relative water content. Although non SA -treated shoot tips were not significantly responsive to increasing levels of PEG in terms of elevated proline content, they responded positively to supply of SA by showing significant increase in proline and chlorophyll contents under water stressed conditions. SA treatments also enhanced plant tolerance against oxidative stress. This was observed through significant reduction in H 2 O 2 and MDA contents of SA -treated shoot tips under water stress conditions. The results revealed that exogenous application of SA helped to reduce the harmful effects of water deficit on banana regenerants in vitro

Fruit regulates seasonal expression of flowering genes in alternate-bearing 'Moncada' mandarin

Background and Aims The presence of fruit has been widely reported to act as an inhibitor of flowering in fruit trees. This study is an investigation into the effect of fruit load on flowering of `Moncada¿ mandarin and on the expression of putative orthologues of genes involved in flowering pathways to provide insight into the molecular mechanisms underlying alternate bearing in citrus. Methods The relationship between fruit load and flowering intensity was examined first. Defruiting experiments were further conducted to demonstrate the causal effect of fruit removal upon flowering. Finally, the activity of flowering-related genes was investigated to determine the extent to which their seasonal expression is affected by fruit yield. Key Results First observations and defruiting experiments indicated a significant inverse relationship between preceding fruit load and flowering intensity. Moreover, data indicated that when fruit remained on the tree from November onwards, a dramatic inhibition of flowering occurred the following spring. The study of the expression pattern of flowering-genes of on (fully loaded) and off (without fruits) trees revealed that homologues of FLOWERING LOCUS T (FT), SUPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1), APETALA1 (AP1) and LEAFY (LFY) were negatively affected by fruit load. Thus, CiFT expression showed a progressive increase in leaves from off trees through the study period, the highest differences found from December onwards (10-fold). Whereas differences in the relative expression of SOC1 only reached significance from September to mid-December, CsAP1 expression was constantly higher in those trees through the whole study period. Significant variations in CsLFY expression only were found in late February (close to 20 %). On the other hand, the expression of the homologues of TERMINAL FLOWER 1 (TFL1) and FLOWERING LOCUS C (FLC) did not appear to be related to fruit load. Conclusions These results suggest for the first time that fruit inhibits flowering by repressing CiFT and SOC1 expression in leaves of alternate-bearing citrus. Fruit also reduces CsAP1 expression in leaves, and the significant increase in leaf CsLFY expression from off trees in late February was associated with the onset of floral differentiation.We thank Dr D. Westall for her help in editing the manuscript. M. C. Gonzalez was recipient of a contract by the Fundacion Agroalimed (Conselleria d'Agricultura, Pesca i Alimentacio, Generalitat Valenciana). This work was supported by a grant from the Instituto Nacional Investigaciones Agrarias, Spain (RTA2009-00147).Muñoz Fambuena, N.; Mesejo Conejos, C.; Gonzalez Más, MC.; Primo-Millo, E.; Agustí Fonfría, M.; Iglesias, DJ. (2011). Fruit regulates seasonal expression of flowering genes in alternate-bearing 'Moncada' mandarin. Annals of Botany. 108:511-519. doi:10.1093/aob/mcr164S51151910

Evaluation of Paclobutrazol Spraying on Salinity Hardiness of Peach- Almond Hybrid (GF677) Rootstock

Introduction: Salinity is a common abiotic stress that seriously affects crop production in some parts of the world, particularly in arid and semi-arid regions. The deleterious effects of salinity on plant growth are associated with low osmotic potential of soil solution (water stress), nutritional imbalance, specific ion effect (salt stress), or a combination of these factors. Paclobutrazol (PBZ), a member of the triazole plant growth inhibitor group, is a broad-spectrum gibberellin biosynthesis inhibitor. Triazoles have both fungal toxicity and plant growth regulatory effects. They also increase tolerance of various plant species to biotic and abiotic stresses, including fungal pathogens, drought, air pollutants, and low- and high-temperature stress. According to our knowledge, there are no reports on the effects of exogenous PBZ enhancing vegetative peach- almond hybrid (GF 677) rootstock tolerance to salt stress. Therefore, the objective of this work was the possibility test of this idea that PBZ application would protect GF 677 rootstock from damaging effects of salinity. Materials and Methods: One-year-old rooted cuttings of GF 677 were grown in in plastic pots in the research greenhouse of Agricultural College, Isfahan University of Technology of Iran. The minimum and maximum temperatures during the experiment period were 19 and 32˚C, respectively. After cutting establishment (3 months), the plants were sprayed twice (with a 7 days interval) with 0 (control), 20 and 40 mg l-1 PBZ to the point of run-off. One week after the second foliar application of PBZ, each plants was subjected to one of several salt stress treatments. The salt treatments (0, 25 and 50 mM NaCl) were applied to the pots intervals in 0.5 l of irrigation water. To avoid osmotic shock, the NaCl concentration was increased gradually. The layout was a 3×3 factorial experiment in a completely randomized design, with four replications. The experimental measurements were carried out 60 days after beginning the salt treatments. Results and Discussion: The results showed that salt stress and application of PBZ significantly affected injury rating valve (IRV). The Injury rating value of plants was found to increase significantly as the salt concentration was raised. After exposure to salt stress those plants that did not receive PBZ exhibited higher symptoms of salt injury. There was a significant interaction between salinity and PBZ application. The lowest IRV in all NaCl concentrations observed when 20 mg l-1 PBZ was applied. Salinity caused significant decrease leaf parameters so that the lowest means of leaf number (12.5) and leaf fresh weight (6.52 g) were recorded at 50 mM NaCl treatment, showing a 55.80% and 41.78% decrease compared with the control, respectively. The application of PBZ significantly increased leaf number, with the largest increase when 40 mg l-1 PBZ was applied. The interaction between salinity and the application of PBZ showed that at 25 mM NaCl maximum valve of leaf number was observed in plants after spraying with 40 mg l-1 PBZ. Relative leaf chlorophyll (RLC) was not affected by salt stress. Application of PBZ significantly increased relative RLC value compared with the control, with the largest increase in RLC measured when 20 mg l-1 PBZ was applied. The interaction between salinity and the application of PBZ showed that at 50 mM NaCl maximum valve of RLC was observed in plants after spraying with 20 mg l-1 PBZ. The proline content of leaves was significantly influenced by the salt stress and PBZ application, but not their interaction. Salinity stress, increased proline content in the leaves of salt-treated plants. At 50 mM NaCl, proline content was maximum compared to those of the controls and other salt levels. PBZ treatment increased proline content in leaves. The highest proline content was obtained from leaves of the plants treated with 40 mg l-1 PBZ (55.62μmol g-1 FW), which was 39.18 % more than the control. Salt stress significantly reduced the relative water content (RWC) with maximum reduction observed in plants grown by 50 mM NaCl. Application of PBZ significantly increased RWC compared with the control, with the largest increasing in RWC at 20 mg l-1 PBZ application. Leaf electrolyte leakage was affected by both salt stress and PBZ application. Salt stress significantly increased leaf electrolyte leakage, with a maximum increase observed in plants grown by 50 mM NaCl. The application of PBZ significantly decreased electrolyte leakage in leaf discs, with the largest decreaseing in leaf electrolyte leakage measured at 20 mg l-1 PBZ application..There was a significant interaction between salinity × PBZ concentrations. However, the greatest decreasing in leaf electrolyte leakage occurred at 40 mg l-1 PBZ in non-saline condition. In this study, the correlation between vegetation and physiological parameters of GF677 plants subjected to salt stress was analyzed. These correlations suggested that salt injury symptoms was negatively correlated with number and fresh weight of a leaf, RWC, RLC, but positively correlated with proline content and leaf electrolyte leakage. Conclusions: in overall, this investigation revealed that salt stress had an inhibitory effect on the vegetative growth of GF 677 plants. The responses of GF 677 plants to the PBZ treatments suggest that the application of PBZ could partially increase the survival capacity of GF 677 plants and protect the plants against injuries such salt stress