Interspecific Cultivars Research Articles

Relative fecundity and ploidy of 34 Buddleja cultivars

Abstract Buddleja davidii (butterfly bush) is a popular landscape plant that is also an invasive species in Oregon and other temperate locations. In Oregon, the plants are classified as a class B noxious weed (which enacts a ban on the species within state lines), with exemptions to the ban based on fertility data or interspecific pedigree alone. To date, there is no evidence that suggests all interspecific hybrids of butterfly bush exhibit reduced fecundity that would lower invasive potential. This study investigates what correlation, if any, there is between interspecific hybridization and lowered fecundity in butterfly bush as well as the cytogenetic effects of interspecific hybridization in the genus. Relative fecundity of 34 Buddleja cultivars of mixed pedigree was analyzed with three populations: the cultivars in a study field, a greenhouse population for controlled crossing, and an open pollinated population generated from cultivars. Interspecific cultivars were consistently both within the highest range of fecundity as well as the lowest range, with greenhouse crossing generally supporting field findings. Flow cytometry conducted on cultivars revealed lower than expected variation in genome size. This study shows interspecific hybridization does not appear to guarantee reduction in fecundity. Species used in this study: butterfly bush Buddleja davidii L.

Influence of Grape Flesh on the Retention and Composition of Polyphenols from Skins and Seeds.

This study examined the impact of grape flesh polysaccharide, protein, and amino acid contents on polyphenol retention from skins and seeds in Pinot noir (Vitis vinifera) and cold-hardy interspecific cultivars Marquette and Frontenac (Vitis spp.). After isolating grape tissues (skin, seed, and flesh), they were soaked either individually or combined with other tissues in a wine-like solution for up to 7 days. Findings revealed that flesh significantly reduces the concentration of condensed tannin, and mono- and diglucoside forms of anthocyanins in the supernatants, due to its rich content in polysaccharides and proteins. Frontenac skin and flesh tissues were the main sources of soluble proteins, amino acids, and soluble polysaccharides. Surprisingly, Marquette exhibited a higher retention of skin tannin than Pinot noir, likely due to its smaller tannin molecular mass, and a potential competitive effect with anthocyanins for the binding sites of flesh.

Consumer Hedonic Testing and Chemical Analysis of Iowa Wines Made from Five Cold-Hardy Interspecific Grape Varieties (Vitisspp.)

<h3>Background and goals</h3> Research into wines made from cold-hardy interspecific hybrids, which have been integral for the establishment of a grape and wine industry through the Upper Midwest, has produced few reports investigating chemical composition and consumer perception. The goals of this project were to i) survey Iowa wine industry members on varieties they thought were best suited for premium wine production and ii) measure consumer hedonic scores and chemical composition of 20 commercial Midwest wines made from five varieties, selected based on the initial survey. Cluster analysis was performed on the sensory data, and correlation of consumer segments with wine composition evaluated. <h3>Methods and key findings</h3> A survey of Iowa industry members identified five cold-hardy interspecific cultivars as growing best in the state: Brianna, Edelweiss, La Crescent, Marquette, and Frontenac. Chemical analyses of 20 commercial wines revealed that titratable acidity weas generally higher than <i>Vitis vinifera</i> wines. The highest protein concentrations were observed in La Crescent and Frontenac wines. Consumers were clustered into five groups based on liking scores and the two largest segments showed a preference for wines with higher residual sugar. <h3>Conclusions and significance</h3> This is the first survey of chemical composition and consumer liking for Midwestern wines produced from cold-hardy interspecific hybrids. The high protein concentrations observed in red and white wines are notable as these may affect tannin extraction and haze formation, respectively. Although average Iowa consumers prefer wines with substantial residual sugar (&gt;20g/L), there is evidence of multiple consumer segments with different residual sugar and varietal preferences.

Risk Assessment of Infectious Endogenous Banana Streak Viruses in Guadeloupe.

Infectious alleles of endogenous banana streak viruses (eBSVs) are present in the genome of all banana interspecific cultivars, including plantains and cooking types. Activation of these infectious eBSV alleles by biotic and abiotic stresses leads to spontaneous infections by cognate viruses and raises concerns about their ability to promote outbreaks of banana streak viruses under field cultivation conditions. We undertook a comprehensive risk assessment study of infectious eBSV alleles of species BSOLV, BSGFV and BSIMV in banana interspecific cultivars in Guadeloupe, a tropical island of the Caribbean where bananas are grown for export and local markets. We carried out a prevalence survey of BSOLV, BSGFV and BSIMV species in a range of cultivars grown in Guadeloupe. Our results suggest that BSOLV and BSGFV infections arise from the activation of infectious eBSVs rather than vector-borne transmission and point to a correlation between altitude and infection rates in interspecific hybrids with AAB genotypes. We studied the dynamics of activation of infectious eBSOLV and eBSGFV alleles by tissue culture and field cultivation in a range of cultivars. We showed that tissue culture and field cultivation trigger distinct activation pathways, resulting in distinct activation patterns. We also showed that activation decreased over time during cell culture and field cultivation and that BSV infections arising from the activation of infectious eBSV alleles cause symptomless infections in the most cultivated plantain in Guadeloupe, French Clair. Overall, our study shows that the risk of BSV outbreaks resulting from the activation of infectious eBSVs in plantain originating from vegetative multiplication is negligible in Guadeloupe.

The effect of harvest time and vintage year on the phenolic composition of Nero and Bianca wines

Abstract Fungal disease resistant (PIWI) interspecific grape varieties are playing an important role as an alternative for organic wine production. Organic (bio) wines are demanded by numerous conscious consumers around the globe. They choose this kind of wines predominantly because of the absence of synthetic pesticides, fertilisers and sustainable agriculture. Resistant grape growing moreover results in additional environmental and health benefits. Nero and Bianca are among Hungary's most promising interspecific grape cultivars gaining international interest recently, there are, however, limited vitivinicultural knowledge on them. Our aim was to examine the flavonoid and anthocyanin composition for both interspecific varieties during different harvest times in two consecutive vintages. The date of harvest and vintage played a significant effect on grape and wine quality.

Evaluation of Iraqi Rice Cultivars for Their Tolerance to Drought Stress

Drought stress is a serious problem around the globe and particularly in the Republic of Iraq. Rice is the third most consumed crop for the Iraqi people; however, its cultivation and production is very low due to several challenges including drought. The current study was performed to evaluate five Iraqi rice cultivars along with relevant (drought-tolerant and drought-susceptible) controls under drought stress, either by treatment with 10% PEG (polyethylene glycol) or through water withholding to induce natural drought stress. The phenotypes of all the cultivars were evaluated and the transcriptional responses of key drought-responsive candidate genes, identified through the EST-SSR marker-based approach, were studied. We also studied transcript accumulation of drought-related transcriptional factors, such as OsGRASS23, OsbZIP12, and OsDREB2A. Moreover, the reference cultivars also included a drought-tolerant inter-specific cultivar Nerica 7 (a cross between Oryza sativa ssp. indica X O.glaberrima). Among the cultivars, the more drought-tolerant phenotypic characteristics and higher transcript accumulation of drought-related marker genes OsE647 and OsE1899 and transcriptional factors OsGRASS23, OsbZIP12, and OsDREB2A were observed in four (out of five) significantly drought-tolerant Iraqi cultivars; Mashkab, followed by Furat, Yasmen, and Amber 33. On another note, Amber Barka was found to be significantly drought susceptible. Mashkab and Amber Barka were found to be the most drought-tolerant and-susceptible cultivars, respectively. The identified tolerant cultivars may potentially serve as a genetic source for the incorporation of drought-tolerant phenotypes in rice.

ASSESSMENT OF ANTIOXIDANTS BY HPLC-MS IN GRAPEVINE SEEDS

It is well known, that grapevine seeds are rich in significant antioxidants. However, the issue of dealing with the analysis and comparison of antioxidant components in the seeds of Vitis vinifera L. in individual cultivars has not yet been sufficiently studied. The experiment was performed with extracts of three varieties (Blaufränkish, Italian Riesling and Cabernet Moravia) and three interspecific cultivars (Nativa, Marlen and Kofranka). Contents of nine major flavonoids (apigenin, astragalin, hyperoside, isorhamnetin, kaempferol, myricetin, quercetin, quercitrin and rutin) and two procyanidins (procyanidin A2 and procyanidin B1) were assessed by the HPLC/MS method. The highest contents of antioxidants were found out in interspecific cultivars Marlen and Nativa while the lowest one was assessed in the cultivar Cabernet Moravia. The most represented flavonoid was hyperoside (cultivar Marlen – 15.66 mg∙l–1), least represented was kaempferol (cultivar Cabernet Moravia – 1.81 μg∙l–1).

Nonlinear Behavior of Protein and Tannin in Wine Produced by Cofermentation of an Interspecific Hybrid (Vitis spp.) and vinifera Cultivar

Wines produced from red interspecific hybrid grape cultivars (Vitis spp.) typically have lower tannin concentrations than wines produced from vinifera cultivars, which can be attributed to the lower concentration of tannins and higher concentration of tannin-binding proteins of interspecific cultivars. Tannin in wines produced from hybrid cultivars may be increased by blending hybrids with vinifera. We hypothesized that blending of grapes prior to fermentation (cofermentation) would result in final wine tannin concentrations lower than those predicted from the individual components due to protein-tannin binding, but that this effect would be absent from monovarietal wines blended postfermentation. To evaluate this hypothesis, a high tannin V. vinifera cultivar (Cabernet Sauvignon) was blended with an interspecific hybrid (Marquette) at different ratios either before (cofermentation) or after fermentation over a two-year period. The tannin and protein concentrations of the wines were measured by methyl cellulose precipitation assay and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, respectively. Tannin and protein concentrations in blended wines were compared to values predicted from the linear combination of the two monovarietal wines. Cofermented blends with a high proportion of Marquette had up to 25% lower tannin than predicted, but observed and predicted tannin concentrations did not differ for most cofermentations and postfermentation blends. However, protein concentrations for many of the blends—especially from cofermentation—were lower than predicted values (>50% in some cases). Loss of protein due to adsorption to tannin was well modeled by a Freundlich adsorption isotherm.

Grape quality and ornamental potential of interspecific cultivars for temperate climate vineyards

ABSTRACTInterspecific grapevine cultivars are the crossing product of two or more Vitis species. Due to the lack of information regarding the technological potential and quality characteristics of interspecific cultivars created in the last decades, the aim of this work was to evaluate the physico-chemical characteristics and physio-morphological particularities of grapes and leaves of three interspecific cultivars (‘Purpuriu’, ‘Radames’ and ‘Moldova’), highly demanded for planting in the temperate climate area, having the hybrid cultivar ‘Villard blanc’ as common genitor. Cultivars reached grape maturity in mid to late September, forming red to dark red-seeded grapes. Ripe grapes showed a balanced sugar/acid ratio, a high content of nitrogenous compounds and good antioxidant activity due to rich polyphenolic content. Ripe berries showed high resistance to mechanical deformations, proving an increased resistance to postharvest handling. Moreover, leaf shape and size and their pigment composition indicated a high ornamental potential of the studied cultivars. These research findings contribute to a better understanding of the economic, nutritional and ornamental potential of valuable grapevine hybrids and hence their value for further breeding programs.

Biochemical composition of different table grape cultivars produced in Slovenia

ABSTRACTIn a three-vintage (2014–2016) experiment, the fruit quality of 20 table grape cultivars was observed. The morphometric and chemical characteristics of the berries were evaluated at the edible grape stage, using OIV descriptors, colorimeter (CIRG index) and HPLC for measurements of sugars, organic acids and vitamin C contents. The cultivars ‘Michele Palieri’ and ‘Italia’ had significantly the highest berry weight (8.2 to 9.7 g), while ‘Perlette’, ‘Esther’, ‘Nero’, ‘Panse precoce’ and ‘Chasselas rouge’ had a lower (2.1 to 2.7 g) weight. Significantly, the lowest CIRG index was found with the cultivars ‘Victoria’, ‘Italia’ and ‘Perlette’ (0.99 to 1.3), and the highest with ‘Perlon’ and ‘Muscat de Hambourg’ (4.8 and 5.2, respectively). Berries of ‘Muscat bleu’ (147.3 g/kg FW) and ‘Nero’ (133.3 g/kg FW) had significantly the highest sugar content, while ‘Michele Palieri’, ‘Victoria’, ‘Italia’, ‘Matilde’ and ‘Queen of vineyards’ (75.9 to 92.08 g/kg FW) had the lowest. The highest organic acid contents were achieved by ‘Ribol’, ‘Perlette’, ‘Italia’, ‘Muscat bleu’ and ‘Lival’ (9.6 to 10.8 g/kg FW), while ‘Queen of vineyard’, ‘Ora’, ‘Perlon’ and ‘Victoria’ (5.8 to 7.1 g/kg FW) were the lowest. In terms of the sugars/acids ratio, ‘Ora’ had the highest (19.1), resulting in the sweetest taste, while ‘Italia’, with a ratio of 8.9, had a sour taste. However, ‘Panse precoce’, ‘Matilde’ and ‘Queen of vineyards’ had significantly the highest content of vitamin C (7.3 to 9.5 g/kg FW), while ‘Muscat bleu’, ‘Nero’, ‘Panse precoce’ and ‘Ribol’ had the highest total phenolics (1.27 to 1.57 g GAE/kg FW). The results suggest that the studied interspecific grapevine cultivars (‘Muscat bleu’, ‘Esther’, ‘Nero’ and ‘Presentabil’) showed an interesting chemical composition, while morphometrically they still fall behind Vinifera varieties.

Histoire de la vigne sauvage, Vitis vinifera ssp. sylvestris, en Camargue / Wild grapevine Vitis vinifera ssp. sylvestris in Camargue, southern France

La vigne sauvage (Vitis vinifera ssp. sylvestris) est en déclin marqué depuis la fin du XIXe siècle. Depuis 2000, l’espèce est considérée en danger critique d’extinction. Des prospections dans la vallée du Rhône ont montré qu’il existait quelques micropopulations jusque dans le delta. Une population de 52 pieds de grandes dimensions et présentant un phénotype sauvage a récemment été découverte en rive gauche du Grand Rhône, dans le boisement privé du mas Saint-Georges. Une recherche pluridisciplinaire a été entreprise sur cette population de vignes afin de reconstituer leur histoire ; les outils utilisés ont été la génétique (effectuée sur 37 individus), l’écologie (dimensions des pieds, identification des porteurs), et la dendrochronologie effectuée sur 5 pieds. L’habitat forestier a également été analysé du point de vue architectural et dynamique de la lumière. Trente et un (31) individus ont été déterminés comme étant de véritables vignes sauvages, dont la diversité est légèrement inférieure à celle des autres populations européennes. Quatre sont des individus hybrides ou introgressés : deux entre vignes sauvages et vignes américaines, et deux entre vignes sauvages et vignes cultivées. Trois haplotypes typiques des vignes sauvages ont été déterminés, indiquant que ce site est à un point de convergence entre populations méditerranéennes du sud, de l’ouest et du centre de la Méditerranée. Le boisement a été suffisamment fermé pour éviter les échanges de pollen avec les vignes américaines échappées. À partir de ces données et de l’analyse des cartes anciennes, il a pu être déduit que ce boisement s’était développé au début du XXe siècle à partir d’un marais asséché par les aménagements hydrauliques. L’âge des vignes, estimé par la dendrochronologie à une fourchette de 38 à 50 ans, pourrait cependant être de l’âge de la forêt. Les vignes se seraient installées lors de la succession forestière. Les caractéristiques architecturales du boisement (à la fois dense et lumineux) ont permis à la vigne de s’y établir sur une longue durée. Actuellement, cette population ne se reproduit plus. Les conditions actuelles ne sont donc plus favorables à l’espèce, à l’inverse des populations échappées de porte-greffes, très abondantes en Camargue. Une protection forte de ces derniers pieds de vigne forestière devrait être mise en place avec l’accord des propriétaires.

Determination of Downy mildew and Powdery Mildew Resistance of Some Grape Cultivars and Genotypes

Different grape cultivars of Vitis species have been cultivated in Turkey since ancient times. A large proportion of these cultivars cannot be cultivated in the humid regions of the country due to downy mildew (Plasmopara viticola) and powdery mildew (Uncinula necator or syn. Erysiphe necator) diseases. Cultivars resistant to these diseases can generally grow without any or fewer fungicide applications. However, there are also differences in the resistance level of cultivars. In particular, Vitis vinifera cultivars, the most widely cultured species, are most affected by these diseases. Thirteen V. vinifera cultivars, eight V. labrusca cultivars and six interspecific cultivars were used in this study, for a total of 27 cultivars. The resistance of cultivars against downy mildew and powdery mildew was determined over two years with natural infection and artificial inoculation applications. Generally, all cultivars showed more resistance to downy mildew, while they also showed lower resistance to powdery mildew. The evaluation based on species found V. vinifera to be the most sensitive. While interspecific cultivars were found to be most resistant to downy mildew, V. labrusca cultivars were the most resistant to powdery mildew. Among cultivars of the same species, however, differences in terms of resistance were observed. These differences can be used in breeding studies in order to obtain new, disease-resistant cultivars, which may be grown commercially to comply with good agricultural practices (GAP) or organic viticulture in the future.

Drought, Salinity and Flooding Tolerance of Oryza sativa, Oryza glaberrima and their Interspecific Cultivars

Drought, Salinity and Flooding Tolerance of Oryza sativa, Oryza glaberrima and their Interspecific Cultivars

Genetic mapping and pyramiding of two new pear scab resistance QTLs

Scab is one of the major fungal diseases infecting pear trees, causing the greatest economic losses. Identifying and pyramiding scab resistance factors should help in breeding new resistant pear cultivars. We have identified and mapped two new pear resistance loci against the fungal pathogen Venturia pirina. The first locus, mapped both as a major gene and as a QTL, is located on linkage group (LG) 01 of the hybrid P3480, deriving from the European pear cultivar ‘Wilder.’ It colocalizes with the Vnk resistance gene found in the Asian pear cultivar ‘Kinchaku’ against Venturia nashicola. A second locus, mapped as a QTL, is located on LG04 of the interspecific cultivar ‘Euras.’ In a small ‘Euras’ × P3480 progeny, seven seedlings carrying the resistant alleles at both loci have been selected using SSR markers.

Genetic diversity and phylogenetic relationships between and within wild Pistacia species populations and implications for its conservation

Although cultivation and utilization of Pistacia are fully exploited, the evolutionary history of the Pistacia genus and the relationships among the species and accessions is still not well understood. The aim of this study was to analyze random amplified polymorphic DNA (RAPD) in a total of 50 accessions of wild pistachio species, which included five populations Pistacia vera, Pistacia khinjuk, Pistacia atlantica, Pistacia mutica, and Pistacia eurycarpa. High levels of genetic diversity were detected within wild pistachio accessions, as revealed by using the unweighted pair-group method with arithmetic averaging and supported via analysis of molecular variance. The objectives of this investigation were to estimate marker indices, polymorphic information contents (PICs), and genetic similarities (GS) for RAPD markers; assess the genetic diversity of Pistacia species, using GS estimated from RAPD fingerprints and molecular characterization; and facilitate the use of markers in inter-specific introgression and cultivar improvement. Out of the 149 polymerase chain reaction fragments that were scored, 146 (97.98 %) were polymorphic. Genetic similarities ranged from 0.3 to 0.86 %, marker indices ranged from 2.98 to 17.74 %, and PICs ranged from 0.80 to 0.99 %. Our results provided great molecular identification of all assayed genotypes, which have shown that there is large quantity of genetic diversity among the pistachio accessions. This finding might render striking information in breeding management strategies for genetic conservation and cultivar development.

Assessment of genetic diversity based on agro-morphological traits and genic microsatellite markers in inter-specific derivatives and cultivars of pigeonpea

In the present study, genetic diversity among 73 genotypes comprising of cultivars and stable inter-specific derivatives from pigeonpea (Cajanus cajan x C. scarabaeoides) was assessed based on thirteen agro-morphological and quality traits and 42 genic microsatellite markers. Cluster analysis based on Tocher's methods of pooled fielddata of agromorphological traits from all three environment and two locations grouped pigeonpea genotypes into nine clusters. Genetic divergence was mainly contributed by days to 50% flowering (30.14%) followed by 100 seed weight (20.78%) and protein content (12.56%). The range of polymorphic information content (PIC) for microsatellites was 0.055–0.695. A total of 104 alleles were amplified with 42 SSR markers with an average of 2.48 alleles per locus. Ten alleles were unique to inter-specific derivatives. Based on Shannon's information index (I), ASSR 17 was the most informative locus for all the genotypes. Two loci, ASSR114 and ASSR317 were polymorphic only among the interspecific derivatives. Cophenetic correlations were statistically significant for phenograms based on Euclidean distances and average Manhattan distance analysis. The first three principal coordinates explained 60.17% and 57.22% of the accumulated variation in case of agromorphological traits and microsatellite data respectively. The information accrued is potential for broadening the genetic base in pigeonpea.

Profiling of primary metabolites in grapes of interspecific grapevine varieties: sugars and organic acids

The quality of grapes is determined above all by the contents of the primary and secondary metabolites. The primary metabolites involve sugars and organic acids, and just these compounds are dealt with in this study. Its objective was to analyse and critically evaluate the primary metabolites in new interspecific varieties and, based on a comparison with European varieties of grapevine (Vitis vinifera L.), to find out the similarities and also possible differences between them. The study evaluates and compares 4 conventional varieties of Vitis vinifera with 11 new interspecific cultivars. The contents and compositions of the individual sugars and acids were estimated by means of the HPLC method. Most of these varieties belong to the group with either medium or low content of malic acid, i.e. with a medium to high &amp;beta; ratio. This corroborates the similarity of interspecific varieties to those of V. vinifera. The cluster analysis identified the existence of two interesting groups of varieties: the first one involved the varieties Riesling, Nativa, Marlen, and Kofranka while the other group consisted of varieties Blaufr&amp;auml;nkisch, Blauer Portugieser, and Laurot. This observation also indicates similarity between Vitis vinifera L. varieties and interspecific cultivars and demonstrates that the contents of the primary metabolites (i.e. sugars and organic acids) are also comparable.

Homoeologous chromosome pairing between the A and B genomes of Musa spp. revealed by genomic in situ hybridization

Most cooking banana and several desert bananas are interspecific triploid hybrids between Musa acuminata (A genome) and Musa balbisiana (B genome). In addition, M. balbisiana has agronomical characteristics such as resistance to biotic and abiotic stresses that could be useful to improve monospecific acuminata cultivars. To develop efficient breeding strategies for improving Musa cultivars, it is therefore important to understand the possibility of chromosome exchange between these two species. A protocol was developed to prepare chromosome at meiosis metaphase I suitable for genomic in situ hybridization. A series of technical challenges were encountered, the main ones being the hardness of the cell wall and the density of the microsporocyte's cytoplasm, which hampers accessibility of the probes to the chromosomes. Key parameters in solving these problems were addition of macerozyme in the enzyme mix, the duration of digestion and temperature during the spreading phase. This method was applied to analyse chromosome pairing in metaphase from triploid interspecific cultivars, and it was clearly demonstrated that interspecific recombinations between M. acuminata and M. balbisiana chromosomes do occur and may be frequent in triploid hybrids. These results provide new insight into Musa cultivar evolution and have important implications for breeding.

Response of interspecific and sativa upland rices to Mali phosphate rock and soluble phosphate fertilizer

In West Africa, two-thirds of upland rice is grown on acidic phosphorus (P)-deficient soils. Phosphorus is one of the most limiting-nutrients affecting crop productivity. A three-year field experiment was conducted on a Ferralsol in Côte d'Ivoire to study the response of four interspecific rice cultivars and a sativa (control cultivar) to Tilemsi phosphate rock (PR) and soluble triple superphosphate (TSP) fertilizer. PR was applied at 0, 150, 300, and 450 kg ha−1 P once in the first year and residual effects were measured in the following years. TSP (0, 50, 100 and 150 kg ha−1 P) was applied yearly. More significant yield increasing (38%) was observed in the second year. Annual application of 50 kg P ha−1 as TSP or a one-time application of 150 kg P ha−1 as PR was the optimum rate for the production of all cultivars. Higher rates of P from TSP (100 and 150 kg P ha−1) gave 2–3 times greater residual P in soil than the optimum rate, inducing no further response of rice. Two interspecific cultivars were identified as the most acid- and low P-tolerant cultivars for improving rice production in West Africa humid forest zone.

Long-term effect of Mali phosphate rock on the grain yield of interspecifics and saltiva rice cultivars on acid soil in a humid forest zone of Côte d’Ivoire

To generate knowledge of upland rice intensification in West Africa, the grain yields of four interspecific cultivars (V2 = WAB450-1 B-P-38-HB; V3 = WAB450-11-1-P-40-HB; V4 = WAB450-11-1-P-40-1-H; and V5 = WAB450-24-3-2-P-18-HB) were compared with that of a soil acidity tolerant sativa (WAB 56-104 = V1) on acid soil at Man in the humid forest zone in Côte d’Ivoire during five cropping seasons (1998, 1999, 2000, 2001 and 2002). Nitrogen and potassium were annually applied at 100 and 50 kg ha-1 respectively. Mali phosphate rock from Tilemsi was applied once in 1998 at 0, 150, 300 and 450 kg P ha-1 in a randomized complete block design with three replications. The results revealed a grain yield ranging from 0.5 t ha-1 to 2.6 t ha-1 with highest productivity of interspecific cultivars V3 and V4 even at 0 kg P ha-1 compared to acid tolerant saltiva (V1). Annual optimum rates of P application were determined at 31.5 and 45 kg P ha-1 respectively for V3 and V4. Applying Mali PR at 31.5 and 45 kg P ha-1 respectively for V3 and V4 was recommended for upland rice intensification in the humid forest zone of Côte d’Ivoire.Keywords: Mali phosphate rock, rice, Côte d’Ivoire, interspecific, acid soil.