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Ginger (Zingiber officinale Rosc.) is a spice, considered as a food medicine because of its numerous beneficial actions on health. However, its production faces several constraints, including the lack of efficient planting material. This is a limiting factor for industrial ginger production. The present study therefore aimed at developing an effective in vitro regeneration protocol for ginger. First, three disinfecting agents (sodium hypochlorite, calcium hypochlorite and mercury chloride) were tested. Then, different combinations of naphthalene acetic acid (0.5 mg/L NAA) and/or benzyl amino purine (1, 3 and 5 mg/L BAP) were evaluated on in vitro shoots regeneration. The results revealed that 3.6% sodium hypochlorite, used for 20 min, induced the best disinfection rates (100%) and healthy buds (84.66%). Furthermore, this study showed that the tested hormonal combinations significantly influenced shoots proliferation in ginger. However, the Proliferation Medium 4 (PM4) [Murashige and Skoog medium including vitamin B5 (MSB) + 0.5 mg/L of Naphthalene Acetic Acid (ANA) + 5 mg/L of Benzyl Amino Purine (BAP)] was the most effective. It induced the highest average number of shoots (22.83 shoots) with an induction rate of 80.50%. As a result of this study, 3.6% sodium hypochlorite used for 20 min and MP4 medium (MSB + 0.5 mg/L ANA + 5 mg/L BAP) were selected for in vitro ginger regeneration.

The cultivation of pineapple contributes 1.6% of the gross Ivorian national product (GDP). However, this crop is facing a severe production crisis due to the aging of the orchards. Revising this sector requires the rejuvenation of orchards with healthy and improved planting material. This work was conducted to study the conditions for the efficient in vitro production of restorative pineapple planting material by somatic embryogenesis. The effects of seven culture media consisting of a different combination of nitrogen sources (casein hydrolyzate, glutamine, and glycine), cytokinins (kinetin or BAP), and auxins (2,4-D or picloram) were tested on somatic embryos induction and maturation in pineapple. Results of the study revealed that EIM1 (EIM added with 3 mg.L-1 picloram, 0.05 mg.L-1BAP, 2 mg.L-1 glycine, 1000 mg.L-1glutamine, 100 mg.L-1casein hydrolyzate) and EIM5 (EIM added with 2 mg.L-1glycine, 100 mg.L-1casein hydrolyzate, 0.2 mg.L-1kinetin) media induced the highest numbers of embryogenic cells, i.e., 154 and 149 cells respectively. Further, the EIM5 medium was more embryogenic, with the most significant number of mature embryos (66 mature embryos), and allowed the observation of all embryonic maturation stages. Embryogenic cell induction in pineapple is thought to be controlled by a low NH4+/NO3- ratio in interactions with phytohormones. In the presence of 2,4-D, embryogenic cell maturation was improved by kinetin addition to the culture medium containing glycine and casein hydrolyzate.

The classic latex harvesting system consists of top-down tapping for nine years before being immediately followed by reverse tapping. This period is often considered too long by the farmers. To address this concern, a study was conducted to determine the best period for down tapping to ensure good performance of agrophysiological parameters in reverse tapping of fast metabolising rubber clones. For this purpose, the PB 260 and IRCA 18 clones were used as plant material in Divo and Daoukro respectively, where the experiments were conducted. Five time frames for down-bleeding (5, 6, 7, 8 and 9 years = control) and two concentrations of ethephon (ET) stimulating paste (2.5 and 5% ET), except for the control which is stimulated only at 5% ET, were tested. The experimental design was a Fisher block design with 9 treatments and 4 replicates. Rubber productivity results (5262 ± 205 and 4951 ± 351 kg.ha-1.yr-1) showed that reverse tapping of these metabolically active clones preceded by 5 and/or 6 years of down tapping was the best (3723 ± 29 kg.ha-1.yr-1 ; control). Rubber production and average annual increment from these tapping periods (4.00 ± 0.42 and 3.60 ± 0.00 cm.yr-1 ; control) were the highest. Productivity gains were 41% for reverse tapping at 6 years stimulated at 5%. The dry notch rate was relatively low (3.30% LEM and 0% dry trees). The physiological profile was generally good. These results indicate that downward bleeding for 5 and/or 6 years allows these clones to express their best potential in reverse bleeding. These results are satisfactory and respond exactly to the concerns of the farmers.

In order to evaluate the effect of early upward tapping on rubber productivity of rubber trees and to determine its proportion relative to downward tapping, a study was conducted at SAPH Divo on the PB 260 clone of the fast metabolic activity class. The experimental set-up was a Fisher block with seven treatments and three replications. Tapping was carried out in d3 with 6 stimulations. Three upward tapping times at 6, 7 and 8 years, each coupled with two concentrations of the stimulating paste 2.5 and 5% of Ethephon and a downwardly tapped control stimulated with 5% of Ethephon were tested. The data collected were for rubber production, isodiametric growth, tapping panel dryness susceptibility and tree physiological profile. The results showed that the different treatments tapped in upward at 6, 7 and 8 years of age significantly improved the productivity of the PB 260 clone relative to the control by downward for nine years. All treatments combined, rubber productivity (4723 kg.ha-1.yr-1) and radial vegetative growth (3.8 cm.yr-1) were good. The gain in rubber productivity of the early upward tapping compared to the downward tapping was 42%. The tapping panel dryness rate was low at 2.6% and the physiological profile of the trees was well balanced. Our results suggest that PB 260, and therefore metabolically active clones, can be tapped in early upward tapping, especially at 6 years of age.

Aims: To evaluate the synergistic action of two elicitors or stimulators of natural plant defense, vacciplant and calliete, on the synthesis of defense metabolites and their impact on tolerance to Mycosphaerella fijiensis, causal agent of the black leaf streak disease (BLSD) in plantain (Musa x paradisiaca L.). Place and Duration of Study: The study was conducted in Abidjan (southern Côte d'Ivoire) in 2019. Methodology: The ability of plants co-treated with vacciplant+calliete to product phenolic compounds was compared to vacciplant and the control. Subsequently, the treated plants were inoculated with the pathogenic filtrate of Mycosphaerella fijiensis in order to induce the black leaf streak disease. Afterwards, the content of phenolic compounds was determined and then their analysis by ultra-high performance liquid chromatography was performed (U-HPLC). Finally, foliar pigments were quantified to have an indication of the sanitary state of elicited and infected plants. Results: plants treated with vacciplant and inoculated, as well as plants co-treated with vacciplant+calliete and inoculated, accumulated more phenolic compounds than the control plants. However, the phenol content of the co-treated plants (191.10 mg/g FL) was higher than that of the plants treated with vacciplant alone (142 mg/g FL). In addition, qualitative analysis by U-HPLC revealed that treated plants synthesized de novo two compounds including trans-resveratrol, a stilbene with significant antifungal activity, in plants co-treated with vacciplant+calliete. In addition, it allowed the plants to acquire a higher leaf greening state than those treated with vacciplant alone, indicating a more intense photosynthetic activity and thus a good sanitary state Conclusion: Vacciplant+calliete has a synergistic effect on the activation of the plantain's defense reactions and thus on the good tolerance to M. fijiensis, an agent of plantain BLSD.

The nine-year period of downward tapping prior to upward tapping is often considered too long and irrelevant. Thus, a study was carried out to determine the minimum time needed for downward tapping for which the agronomic parameters (rubber production, vegetative growth) of the rubber trees could best be expressed in upward tapping. Clones with slow (PB 217 and IRCA 41), moderate (GT 1) and fast (PB 260 and IRCA 18) metabolisms were used as plant material in the experiments carried out in Gagnoa, Bettié, Daoukro, San Pedro and Divo. The rubber trees were tapped in a half-spiral downward direction at different times followed by quarter-spiral upward or upward tapping. The experimental design was a Fisher block design with 9 treatments and 4 replications. The results showed that upward tapping preceded by downward tapping for 5 and/or 6 years was the best regardless of the metabolic activity class of the clone. Rubber production expressed in kg.ha-1. year-1 [Slow (5y-2675 ± 79) (6y-2488 ± 59) (T9y-2238 ± 45); Moderate ((5y-5417 ± 127) (6y-5094 ± 141) (T9y-3993 ± 58); Fast (5y-5210 ± 239) (6y-4733 ± 500) (T9y-3723 ± 245)] resulting from these upward tappings increased with an increasing gradient of clone metabolism without, however, detrimental to vegetative growth (cm. yr-1) [Slow (5 yr-3.90 ± 1.27) (6 yr-4.05 ± 1.48) (T9 yr-3.40 ± 1.13); Moderate ((5 yr-3.02 ± 0.25) (6 yr-2.80 ± 0.05) (T9 yr-2.39 ± 0.02); Fast (5 yr-4.27 ± 0.42) (6 yr-3.97 ± 0.28) (T9 yr-3.60 ± 0.05)]. These results show that upward tapping in year 6 is more advantageous than tapping in year 10.

In order to evaluate the improvement of rubber productivity of rubber trees by late upward tapping. A study was conducted at SCASO (Société Civile Agricole du Sud-Ouest) on the PB 260 clone of the active metabolic class. The experimental set-up is a Fisher block design with eight treatments and three replications. The treatments compared were bled in reverse in the eleventh year of harvest, in quarter spiral every 3, 4, 5 and 6 days, with stimulation frequencies of 6, 8, 10, 12 and 13 times a year. The parameters measured were rubber production, isodiametric growth, sensitivity to dry notching of trees and physiological profile. The results show that the different latex harvesting technologies improve the rubber productivity of PB 260 (5469 kg.ha-1.yr-1) with a low dry-nut rate (1.2%) and satisfactory radial vegetative growth (3.9cm.yr-1). The physiological profile of the trees is balanced, but the treatments significantly influenced the different parameters except sucrose. Trees bled in S/4U d3 gave better results due to their high yield with an acceptable dry notch rate. Late reverse tapping is therefore a good latex harvesting technology for improving rubber productivity after down tapping.

Resistance to internal browning of pineapple fruits depends on several factors such as the cultural techniques through mineral fertilization. The objective of this work is to study the effects of the potassium fertilization for pineapple on internal browning of fruit in post-harvest conservation. The experiments have been carried out on the site of the University Nangui Abrogoua (Abidjan, Côte d’Ivoire) of July 2015 to the end of October 2016. Potassium has been applied according to four modalities of treatments (T0; T1; T2 and T3) made in 2nd, 4, 6 and 7th months (respectively) after plantation. The incidence of internal browning (IB), the phenolic content, sugars and ascorbic acid have been determined after post-harvest conservation of fruit. The activity of phenolic biosynthesis enzymes (PAL and TAL) and oxidation enzymes (PPO and POD) were evaluated. The results showed that BI intensity in pineapple fruit decreases with the potassium amount applied in field. This IB drop was correlated with the content of reducing sugars, total phenols, activity of PAL and the PPO. No symptom of IB was observed on pineapple fruits under treatment T2 (34 g of K2O/plant). Potassium has a depressive effect on phenolic biosynthesis. In effect, it inhibits the IB in the both varieties of pineapple studied that are Smooth Cayenne and MD2.

Secondary metabolites of plants widely used in the medicinal and cosmetic industries, can be produced by tissue culture.In vitroproduction of these secondary metabolites is affected by various factors such as the type and concentration of phyto regulators. In this study, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2-methoxy-3,6-dichlorobenzoic acid (Dicamba) effect on phenolic compounds synthesis as well as Phenylalanine ammonia lyase (PAL), tyrosine ammonia lyase (TAL), Polyphenoloxidase (PPO), peroxidase (POD), Catalase (CAT) and Ascorbate Peroxidase (APX) activities from root explants have been studied. The root explants come from the seedsin vitrogermination of maize irradiated (200 and 300 grays) or not irradiated (control) with gamma radiation. The results obtained showed that the auxin type had a very highly significant effect (p

The objective of the study was to evaluate the effect of methyl jasmonate and ethephon on cotton against Fusarium wilt. As well, cotton plants were treated in the field by methyl jasmonate (MeJA), ethephon (ETH) and the association of methyl jasmonate and ethephon (MeJA + ETH) and inoculated by Fusarium oxysporum f. sp. Vasinfectum (FOV). The incidence of the disease caused by FOV was evaluated every 10 days up to the 150th day after inoculation. The protection afforded to cotton following treatment by stimulators was assessed by determining the mortality rate of plants treated and inoculated FOV compared with untreated and inoculated controls. The degree of protection of cotton from Fusarium wilt was also determined through growth parameters, foliar pigment content (Chlorophylls and carotenoids) and an evaluation of the rate of lines. The results showed better protection of the cotton plants treated by the stimulators and inoculated by FOV through an increase in the number of healthy leaves, stem height, and stem diameter. This protection was also confirmed by an increase in photosynthetic activity of plants and a reinforcement of cell walls. The combination of these two molecules (MeJA + ETH) was better to induce this resistance against FOV compared to each of the two taken separately. The use of natural defence stimulators (SDN) is therefore an effective means of protecting cotton from FOV. Their application in the agricultural environment could contribute to the development of a well-reasoned, sustainable agriculture that is more respectful of the environment and human health.

The oil palm (Elaeis guineensis Jacq.) genetic improvement is based on a recurrent reciprocal selection scheme, involving two groups of populations whose production components are complementary. Group A is essentially coming from Asia, while group B includes African oil palm populations. In order to increase genetic variability and to enrich the agronomic qualities of this group B, a survey was carried out in Western Côte d'Ivoire. Twelve traditional genotypes were collected in the Man area. They are known to produce a rather fluid palm oil but their behavior against Fusarium wilt was unknown. Therefore, these traditional populations were subjected to the Fusarium wilt tolerance test. One hundred and sixty (160) two-months-old seedlings of the traditional accessions were distributed in 8 completely randomized blocks and inoculated by Fusarium oxysporum f. sp. elaeidis. The appearance of external symptoms on inoculated plantlets was observed over the duration of 5 months, and internal symptoms remarked after plantlets dissection. Index of the Fusarium wilt susceptibility of each progeny was determined. A third of traditional genotypes tested (Dompleu Kp 03, Gbangbegouiné Doua 01, Gbangbegouiné Kla 01 and Gbatonguin Yod 02) proved to be highly tolerant to the wilt disease. Four traditional accessions (Bogouiné Sad 02, Dompleu Kp 01, Dimgouin Zoh 02 and Blolé Dio 05) showed low tolerance, while the last four traditional genotypes (Blolé Oul 03, Koutongouiné Iba 02, Blolé Dio 02 and Dompleu Dou 03) were sensitive to the wilt disease.

La fusariose causee par Fusarium oxysporum f. sp. vasinfectum est une maladie qui entraine le plus de dommages dans la culture cotonniere. Cependant, l’utilisation de pesticides notamment les fongicides comme solution pour faire face a l’agent pathogene s’est averee non seulement inefficace mais entraine des problemes de toxicite, de pollution de l’environnement, de sante et meme de biodiversite. L’objectif de ce travail a ete d’etudier la variabilite de la production de composes phenoliques impliques dans le systeme de defense naturelle du cotonnier. Ainsi, l’application des eliciteurs MeJA et FOS11 (10%) sur les plants de cotonnier suivis d’inoculation a FOV a permis la synthese de novode composes phenoliques en plus des composes preexistants. Par ailleurs, l’accumulation des composes phenoliques a ete amplifiee suite a l’application de ces deux eliciteurs suivie de l’inoculation a FOV. Les plants de cotonnier ont ete donc equipes de composes qui ont anticipes l’attaque de FOV. Toutefois, la FOS11 (10%) a induit la production d’un plus grand nombre de composes phenoliques que le MeJA. La FOS11 (10%) a donc ete retenu comme meilleur eliciteur naturelle de la stimulation des defenses naturelles du cotonnier. Fusarium blight caused by Fusarium oxysporum f. sp. vasinfectum is a disease that causes the most damage in cotton growing. However, the use of pesticides, especially fungicides as a solution to the pathogen, has proven to be not only ineffective but also leads to problems of toxicity, environmental pollution, health and even biodiversity. The objective of this work wasto study the variability of the production of phenolic compounds involved in the natural defense system of the cotton plant. Thus, the application of the MeJA and OSF 11 elicitors (10%) on the cotton plants followed by inoculation with FOV allowed the de novo synthesis of phenolic compounds in addition to the preexisting compounds. Moreover, the accumulation of phenolic compounds was amplified following the application of these two elicitors followed by inoculation with FOV. The cotton plants were therefore equipped with compounds that anticipated the FOV attack. However, OSF 11 (10%) induced the production of more phenolic compounds than MeJA. OSF 11 (10%) was therefore chosen as the best natural elicitor of the stimulation of the natural defenses of cotton.

Impact of benzothiadiazole (BTH) and salicylic acid (SA), as natural defense stimulators, was tested on phenolic compounds biosynthesis in cotton (Gossypium hirsutum L., cv. Y764AG). Cotton leaves were spread with BTH and SA at six concentrations (1.0, 2.5, 5.0, 8.0 and 10 mM) and incubated during 24, 48, 72 and 96 h. Plant-treated with 1.0 mM BTH and 2.5 mM SA, respectively 96 and 24 h of incubation time induced the highest levels of phenolic compounds for each type of stimulator. These both concentrations were then combined for the co-treatment of the plants, with the previous incubation times retained. Results showed that co-treatment with BTH and SA was not beneficial for the induction of phenolic compounds compared to elicitors used alone.

The improvement of pineapple (Ananas comosus var. Smooth Cayenne) by means of in vitro culture is less studied in Côte d'Ivoire despite the importance of this plant for this country’s economy. Our work consisted in highlighting nature and concentration effects of carbohydrates on the proliferation of calli in pineapple as a prelude to efficient embryogenesis. Callus proliferation was carried out from the base of pineapple vitroplants leaves. Thirty (30) explants were cultured on the tested culture medium. MS medium (micro- and macro elements of Murashige and Skoog) supplemented with vitamin Gamborg B5 was used as base medium to which were added 0.05 mg/L BAP, 3 mg/L picloram, 2 mg/L glycine, 1,000 mg/L glutamine, 100 mg/L casein hydrolyzate and 30 g/L carbohydrate. Sucrose was tested at different concentrations (20, 25, 30, 35 and 40 g/L). The results revealed that callus proliferation is strongly influenced (p ˂ 0.0001) by nature and concentration of carbohydrate. Sucrose with the highest dry matter content (61.34 mg) has a higher callogenic potential than the other studied carbohydrates. The concentration of 30 g/L sucrose significantly improved the calli proliferation in pineapple. Galactose and maltose were less favorable to proliferation.

The cultivated rubber clones are sensitive to latex harvesting regimes according to their laticiferous metabolism. Thus, in order to determine the best latex harvesting systems of clones with low or slow metabolism, six latex harvesting technologies are applied to them in a bulk statistical device from Fisher to four rehearsals. The rubber is tapped in downward half spiral stimulated or not for nine years after the opening of the tapping panel. The agronomic parameters (production, vegetative growth), the tapping panel dryness and those of the latex micro diagnosis were evaluated. The results indicate that these clones independently of the latex harvesting system have good rubber productivity (2310 kg.ha -1 .y-1 ) with good radial vegetative growth (2.9 cm.y -1 ). Their trees show a well-balanced physiological profile and an acceptable sensitivity to the tapping panel dryness (4.9%). However, the physiological index, the bark consumption and the sensitivity to the tapping panel dryness lead to retain the latex harvesting technologies "S/2 d3 6d/7 Pa1(1) ET2.5% 4/y, S/2 d4 6d/7 Pa1(1) ET2.5% 4/y and S/2 d4 6d/7 Pa1(1) ET2.5% 8/y” for the best. This index, favorably influencing the choice of technologies adapted to clones with active metabolism, contributes to the modern and efficient management of a rubber plantation.

The cultivated rubber clones are sensitive to latex harvesting regimes according to their laticiferous metabolism. Thus, in order to determine the best latex harvesting systems of clones with active or rapid metabolism (IRCA 18, IRCA 130, PB 235, PB 260 and PB 330), six latex harvesting technologies are applied to them in a bulk statistical device from Fisher to four rehearsals. The rubber is tapped in downward half spiral stimulated or not for nine years after the opening of the tapping panel. The agronomic parameters (production, vegetative growth), the tapping panel dryness and those of the latex micro diagnosis were evaluated. The results indicate that these clones independently of the latex harvesting system have good rubber productivity (2310 kg.ha -1.y1) with good radial vegetative growth (2.9 cm.y-1). Their trees show a wellbalanced physiological profile and an acceptable sensitivity to the tapping panel dryness (4.9%). However, the physiological index, the bark consumption and the sensitivity to the tapping panel dryness lead to retain the latex harvesting technologies “ S/2 d3 6d/7 Pa1(1) ET2.5% 4/y and S/2 d4 6d/7 Pa1(1) ET2.5% 4/y ” for the best. This index, favorably influencing the choice of technologies adapted to clones with active metabolism, contributes to the modern and efficient management of a rubber plantation.

Lagenaria siceraria Molina has a high productive potential of fruits but the seeds weight remain low. The aim of this study is to regenerate doubled haploids from androgenesis in order to create genotypes with good agronomic characteristics. For this purpose, flower buds of six accessions namely NI185, NI202, NI215, NI276, NI356 and NI271 were pre-treated at 4 °C for 0, 1, 2, 4, 6, 7 days. To assess the ability of these accessions to induce callus, the anthers excised from the collected floral buds were cultured following two standard protocols referred to as Metwally et al. and Kumar and Murthy, respectively. Histological sections were performed with buds of different sizes in order to select pollen at uni-nucleate stage, the most appropriate for the androgenesis. The histological sections showed that the pollen is at uni-nucleate stage when the bud size varied from 5 to 7 mm. No callus production was observed with the protocol of Metwally et al. whereas a significant formation of callus were expressed on medium corresponding to the protocol of Kumar and Murthy. The best rate (79%) of callus induction was obtained after one and two days of pre-treatment at 4 °C. The highest rate of callus induction was observed with the accessions NI271, NI276 and NI356.© 2015 International Formulae Group. All rights reserved.Keywords: Cucurbitaceae, anther culture, thermal shock, androgenesis, plant regeneration

Pineapples are traditionally propagated by suckers. The advantage of using tissue-cultured plants for pineapple production has been demonstrated in recent years. Despite the large-scale use of micropropagated plants in the subtropical regions, little information is available on the nutritional quality of the fruit. Some morphological states (weight and length of fruit, diameter of fruit and heart of fruit), physico-chemical aspects (pH, titratable acidity, soluble solids and water contents), biochemical contents (vitamin C, total phenols, total dietary fiber, total free amino acid, lipids, protein and minerals) and sensorial attributes (appearance, color, firmness, odor, sweetness, tartness and acceptability) were studied. This, in order to assess nutritional properties and consumer acceptability of fruits (FR) derived from conventionally-propagated sucker, fruits (FM) derived from in vitro propagation plant and fruits (FE) derived from somatic embryogenesis regenerated plants. Significant differences were found in weight, length, diameter, heart diameter and commercial interest of the different fruits, and also between other chemical parameters (pH, soluble solids, titratable acidity, total dietary fiber, total sugars, protein, amino acid, phenol and vitamin C). Values of the ratio between soluble solids and acid were the lowest in the fruit FR, while they were the highest in the fruit FE compare to the fruit FM. In addition, the mineral analyzes show that K, Ca, Mg and P are the major minerals found in pineapple fruits and Al, Fe, Na and Zn are present in trace. A taste panelist preferred the tartness of the fruit FE as well as sweetness and tartness of fruit FM. The quality of the fruits coming from in vitro culture appeared to be the best. Plants resulting from tissue culture can be recommended for large-scale farming.