Phytochemistry 93, 41–48. Plant Growth Dev. Plant Soil 359, 107–120. Three rice varieties, Umgar (YUNLU 30 originating from China), Kosti1 and Kosti2, released for commercial production in Sudan (Nyachae, 2011), were obtained from the ARC, Sudan. The corresponding numbers for Kosti2 were 0, 0, 0.3, 1.7, 1.0, and 1.7, respectively. Crop Sci. Weed Sci. abstract Nodal root anatomy was compared among twelve upland and lowland rice (Oryza sative L.) varieties with tropical origin which were grown in hydroponic culture and under field conditions. The original root exudates from the rice varieties induced negligible to little (0.1–16.3%) germination (Figure 8A). Emergent Striga plants per pot were counted weekly from 49 to 119 DAS for the first experiment, at 1140, 1453, 1907, 2112, 2305, 2493, 2689, 2875, 3023, and 3178 GDDs for the second experiment and at 1111, 1286, 1485, 1696, 1908, 2121, 2339, 2530, 3013, and 3203 GDD for the third. FIGURE 2. The possibility of having differential response of the rice varieties to Striga due to variations in root size and architecture and/or vertical distribution of the parasite seeds cannot be ruled out. 3, 1159–1166. Low relative humidity, 37.5% on average hourly measurement, was predominant from 61 DAS onward. The Striga seedlings at stage IV, classified as successful parasitism with healthy shoots, varied widely among varieties and represented 2–63.3% of the original inoculums (Figure 2D). (2007). Three rice varieties, Umgar (YUNLU 30 originating from China), Kosti1 and Kosti2, released for commercial production in Sudan (Nyachae, 2011), were obtained from the ARC, Sudan. A full-length enriched cDNA library and expressed sequence tag analysis of the parasitic weed, Striga hermonthica. Nitrogen, as urea (165 kg N ha-1), was applied as split equal doses at 14, 35, and 49 DAS. Breed. The rainfed lowland NERICA development was facilitated through the shuttle-breeding approach with national programs in West and Central Africa to accelerate the selection process and achieve wide adaptability of the rainfed lowland NERICAs. 1, 229–249. For the second experiment, six rice varieties were used. Furthermore, spatial and temporal stability and durability of Striga resistance have to be further ascertained taking into account variability in environmental conditions and virulence between S. hermonthica ecotypes. Variation for host range within and among populations of the parasitic plant Striga hermonthica. doi: 10.1007/BF00139766, Lendzemo, V. W., and Kuyper, T. W. (2001). Traditional rice varieties, which include pigmented and aromatic rices, possess excellent eating qualities. ARC, Agricultural Research Corporation; DAI, days after inoculation; DAS, days after sowing; DW, dry weight; GDD, growing degree days. 56, 356–363. Increasing rice production in sub-Saharan Africa: challenges and opportunities. Rodenburg, J., Cissoko, M., Kayeke, J., Dieng, I., Khan, Z. R., Midega, C. A. O., et al. Plant Sci., 13 May 2016 A response to Orr et al. J. Cultivation of upland varieties is also seasonal. Adv. Weed Res. The respective ethyl acetate extracts, pooled, dried over anhydrous sodium sulfate, were evaporated in vacuo at 40°C to dryness. The disks were allowed to dry at room temperature for 2 h. Each treated disk was overlaid by a disk containing conditioned Striga seeds and moistened with distilled water (40 μL). The results from the pot and semi-controlled open air experiments corroborated the strong Striga-resistance of NERICA5 as identified in the rhizotron experiment. Int. Ali, R. A., El-Hussein, A. Sci. (2008). A., Xie, X., Yoneyama, K., and Takeuchi, Y. Failure of the parasite to attach to the host roots (stage I) due to lack of haustorium formation, is common to all varieties, however, inter-varietal differences were considerable. Although there are several Striga-resistant rice varieties, as noted above, crop resistance against one S. hermonthica population may not always be effective against other populations (Huang et al., 2012). Available at: http://afsta.org/media/baseline-studies/ [accessed February 29, 2016]. Pooled across sampling date, root exudates from Umgar and Nipponbare exhibited significantly lower (p < 0.05) activities compared to those from NERICA4, NERICA13, and NERICA18. 178, 157–166. Prior to heading, all pots were irrigated at 2-days intervals. Bars indicate standard errors of each mean value of six replications. The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. Privacy Policy | Politique de confidentialité. Perennial Upland Rice program, Philippines, 1990-2001. Total precipitation was 95.8 mm and the average daily solar radiation was 17.8 MJ m-2 d-1. The variance could be attributable to differences in Striga populations used in the previous studies and the present one. However, it sustained higher Striga emergence in the pot and semi-controlled open air experiments. In addition, root endodermis structure did not explain the difference between a resistant variety (Nipponbare) and a susceptible variety (Kasalath; Gurney et al., 2006). doi: 10.1111/j.1365-3180.2006.00507.x, Wopereis, M. C. S., Diagne, A., Rodenburg, J., Sié, M., and Somado, E. A. Sixty rainfed lowland NERICA varieties (NERICA-L), with yield potential of 6 to 7 tons per hectare and good resistance to major lowland stresses, were selected by farmers in several African countries through the PVS process. doi: 10.1071/PP98070. *Correspondence: Hiroaki Samejima, samehiro@agr.nagoya-u.ac.jp, †Present address: Abdel G. Babiker, National Center for Research, P.O. It is grown in moderately fertile garden soil without the need for more irrigation than other grain or vegetable crops. It also revealed that a single variety, Chhomrong Dhan (CD) originating from Nepal and released in 2006 was by far the most widely cultivated variety and accounted for 82.5% of the total acreage of upland rice. Second, group discussions in primary villages to identify the main secondary villages to which primary village rice growers had supplied Ashoka seed. Number of emergent S. hermonthica plants per 10 rice hills in an artificially infested field. Afr. Original (A), 10-time concetrated (B), 25-time concentrated (C) and 50-time concetrated (D) root exudates were used in the germintion test. The results indicate that these technologies are now spreading in upland areas. Effect of varying supply of manganese on growth and yield. In total there are now 82 NERICA varieties – 18 upland, 60 rainfed lowland and 4 irrigated varieties. Very hardy and has some frost tolerance. Aerobic rice, upland rice, water stress, traditional varieties, yield potential, harvest index. Impact Factor 4.402 | CiteScore 7.8More on impact ›, Advances in Parasitic Weed research 29, 210–221. The differential performance of these varieties may be attributed to the relatively high germination inducing activity of root exudates of NERICA13 compared to the other varieties. Furthermore, hypersensitivity, which has been observed in sorghum (Mohamed et al., 2003), was not observed in this study. Life Sci. “Haustorium initiation and early development,” in Parasitic Orobanchaceae. “NERICA: origins, nomenclature and identification characteristics,” in NERICA: The New Rice for Africa—A Compendium, eds E. A. Somado, R. G. Guei, and S. O. Keya (Cotonou: Africa Rice Center (WARDA)), 10–30. NERICA-4, which is tolerant to drought and phosphorus deficiency, is the most widely adopted upland variety, grown in more than 10 SSA countries. Sci. In particular, upland rice and forest soil (as a control) were acidic, contain low nitrogen content and CEC value at 0 – 20 and at 20 – 40 cm depth. FIGURE 8. Dro1, a major QTL involved in deep rooting of rice under upland field conditions. Striga had no significant adverse effects (p > 0.10) on the total above-ground parts and panicle DW in Umgar, NERICA5, and NERICA13 (Table 1). Further the resistance of NERICA5, a variety reported to be endowed with a broad spectrum resistance to Striga species and ecotypes, at least to one resident Striga population in Sudan was clearly indicated. The scalability of the NERICA varieties has already been demonstrated in Africa. They are early-maturing (75-100 days) and are relatively tolerant of major stresses of Africa’s harsh growth environment. Amusan, I. O., Rich, P. J., Menkir, A., Housley, T., and Ejeta, G. (2008). doi: 10.1007/978-3-642-38146-1_7, Uga, Y., Okuno, K., and Yano, M. (2011). Evaluation the resistance of six rice cultivars to drought: restriction of deep rooting and the use of raised beds. The potted experiment was carried out in the screen house of the Department of Crop Science and Horticulture, Federal University Oye-Ekiti, Ikole campus in 2015 to screen and evaluate the performance of upland rice varieties in inundated soils with a view to selecting the suitable variety or varieties that will fit into the existing niche in the inland valley. The percentage values in germination tests were transformed to arcsine, compared by Tukey’s HSD test and back-transformed (Kgosi et al., 2012). (2013). NERICA13, at seed bank size of 16, 32, and 48 mg Striga, supported 1.8, 5.7, and 3.8 emergent Striga plants per pot, respectively. Pooled across sampling dates, root exudates from Umgar exhibited significantly lower (p < 0.05) activities compared to those from NERICA4, NERICA13, and NERICA18 and there was no significant (p > 0.05) difference among Umgar, Nipponbare, and NERICA5. Percentage out of 30 seedlings of S. hermonthica at stage (A) I, failure to attach to the root due to a lack of haustorium formation (Figure 1a); (B) II, successful attachment but no shoot elongation (Figures 1b–d); (C) III, shoot necrosis after reaching the four or more leaf pairs stage (Figures 1e,f); and (D) IV, successful parasitism with healthy shoots (Figures 1g,h) on the roots of five rice varieties in the second rhizotron experiment at 21 DAI. The technologies considered were improved upland rice varieties and terraces. The corresponding numbers of emergent Striga plants were 11.7, 16.4, and 8.7 for NERICA4, 7.4, 5.7, and 3.8 for Kosti1 and 5.7, 15.3, and 10.0 for Kosti2, respectively. Rice planting and husbandry practices were as recommended by ARC, Sudan for upland rice production under supplementary irrigation. The rice above-ground parts, severed into panicles and vegetative parts, were oven dried at 80°C for 3 days and weighed. Its multiple resistance phenotypes to Striga would confer a wider ecological amplitude. Appl. Achievements and impact of NERICA on sustainable rice production in sub-Saharan Africa. The high post-attachment resistance of Umgar was partly attributable to the developmental arrest of Striga at stage III, namely shoot necrosis after reaching the four or more leaf pairs stage. Umgar supported no emergent Striga plants at seed bank size of 0–8 mg. Newsl. FIGURE 7. The 10, 25, and 50-time concentrated root exudates of sorghum induced 89.4, 96.4, and 95.1% germination, respectively. doi: 10.1111/j.1469-8137.2008.02484.x, Swarbrick, P. J., Scholes, J. D., Press, M. C., and Slate, J. Several hundred interspecific progenies with promising agronomic performance were generated, increasing the biodiversity of rice. 28 Identification of rice varieties with resistance to resident Striga populations and adaptability to the target environment is imperative to evade the risk. The seedlings were transplanted each, to a 50-mL plastic tube wrapped in aluminum foil to exclude light. The synthetic germination stimulant GR24 was used at 0.34 μM as a positive control and tap water and distilled water were used as a negative controls. (2013) using Striga seeds that had been conditioned under sterilized conditions for 12 days on 8 mm diameter glass fiber disks (approximately 50 seeds per disk). This study was supported by a JST/JICA SATREPS (Japan Science and Technology Agency, Tokyo Japan and International Cooperation Agency, Tokyo, Japan) and JSPS KAKENHI Grant Numbers 23790015 and 26450019 (Japan Society for the Promotion of Science, Tokyo, Japan). Jobs | Tenders | Training | Contact  Upland rice varieties are mostly grown as a low-yielding subsistence crop to give stable yields under the adverse environmental conditions of the uplands. Each seedling was transferred to a 10-mL test tube and grown hydroponically in 40% Long Ashton solution for 6 days. To address the problem of erosion in upland rice-growing regions, the International Rice Research Institute (IRRI) initiated a breeding program for perennial upland rice in the mid-1990s. (2011) reported that NERICA1 showed high resistance to S. hermonthica collected from maize (Zea mays L.) in Kenya and sorghum [Sorghum bicolor (L.) Moench] in Sudan and to S. asiatica from maize in the USA and rice (cultivar Supa) in Kenya. 62, 2485–2495. doi: 10.1016/S0167-8809(00)00293-0, López-Ráez, J. New Phytol. New Phytol. The authors are indebted to Mr. Ismail Ibrahim Elmunsor and Ms. Chizu Yoshimoto for daily maintenance of plant materials used in the experiments. One day prior to sowing, 100 g of compost was mixed with the soil in each pot. Laboratory, pot, and semi-controlled open air experiments were performed to evaluate resistance of selected rice varieties in Sudan to a resident S. hermonthica population. Developmental arrest of the parasite at stage II (successful attachment but no shoot elongation) contributed to the high post-attachment resistance in NERICA13, NERICA5, and Umgar. Rice Comm. FIGURE 3. No use, distribution or reproduction is permitted which does not comply with these terms. Upland Rice. Treatments were arranged in a split-plot design. NERICA5, which was reported as a variety with broad spectrum of resistance to Striga species and ecotypes, exhibited resistance against a population of S. hermonthica resident in Sudan. The germination test using serial concentration ruled out the possibility of inhibition of Striga seed germination by high concentration of the stimulant. Int. The NERICA varieties for various rice ecologies are a significant international public good. Nipponbare was not included because of lack of adaptability to upland rice growing environment confirmed in the second pot experiment and the semi-controlled open air experiment mentioned below here. Physiology and histology of resistance to Striga hermonthica in Sorghum bicolor var. New Rice for Africa (NERICA) cultivars exhibit different levels of post-attachment resistance against the parasitic weeds Striga hermonthica and Striga asiatica. FIGURE 4. However, significant reductions (p < 0.01 or 0.05) in total above-ground parts and panicle DW were observed in NERICA4, NERICA18, and Nipponbare (Table 1). Theor. doi: 10.1111/j.1365-3180.2012.00912.x, Kim, S. K. (1996). Plant Biol. Molecular responses of Sorghum to purple witchweed (Striga hermonthica) parasitism. Disks containing conditioned Striga seeds, dapped on a filter paper to remove excess water, were treated with an aliquot (20-μL each) of the original root exudates. Germination inducing activity of root exudates from Umgar, NERICA5, NERICA13, Nipponbare, NERICA4, and NERICA18 grown in a growth chamber. 179, 515–529. It supported 1.3 emergent Striga plants per pot at a seed bank size of 16 mg. In addition, comparative studies on reaction of Umgar, Kosti1 and Kosti2, released varieties for commercial production in Sudan, to the parasite were performed in two pot experiments. Addressing current and future problems of parasitic weeds in rice. TABLE 2. Yield physiology of rice. doi: 10.1111/j.1469-8137.2009.02840.x, Keywords: NERICA, parasitic weed, pre-attachment, post-attachment, rhizotron, Citation: Samejima H, Babiker AG, Mustafa A and Sugimoto Y (2016) Identification of Striga hermonthica-Resistant Upland Rice Varieties in Sudan and Their Resistance Phenotypes. Bars indicate standard errors of each mean value of four replications. It is also an intergovernmental association of African member countries. Roots of each 20-days-old rice seedling, in a rhizotron, were inoculated with 30 pre-germinated Striga seeds and subsequently incubated in the same growth chamber. Nipponbare and Kasalath were obtained from the GenBank of the National Institute of Agrobiological Science, Japan. Crop Sci. Rich, P. J., Grenier, C., and Ejeta, G. (2004). However, involvement of germination inhibitors cannot be ruled out as the solvent extraction may exclude hydrophilic inhibitors (Yoneyama et al., 2010). 30, 843–879. The lower germination inducing activity of root exudates from Umgar showed pre-attachment resistance. The Journal of Agricultural Science, Vol. Until recently, there was limited research on breeding upland rice varieties. Agric. Genet. AfricaRice est aussi une association inter-gouvernementale composée de pays membres africains. Popular African upland rice variety Nerica4 performs poorly under phosphorus (P) deficiency; the objective was to identify plant and soil traits likely to improve its P efficiency. NERICA13, as revealed by the rhizotron experiment, showed post-attachment resistance comparable to Umgar and NERICA5. The present study aimed to evaluate the effect of rice varieties and cultural practices on termite populations and damage in the field. Number of emergent S. hermonthica plants per pots planted with rice. (2011) reported that NERICA1 and NERICA10 exhibited the highest post-attachment resistance to S. hermonthica and Striga asiatica (L.) Kuntze. One day before each sampling date, the roots were thoroughly rinsed with tap water and the nutrient solution in the plastic tubes was replaced with tap water. Lack of water control, iron toxicity, weeds, and highly destructive diseases and pests are the major challenges to rice production. Effects of S. hermonthica on rice total above-ground parts and panicle DW in a semi-controlled open air experiment in 2012. The developmental arrest of Striga at stage III, necrosis of the parasite shoot, was observed in seven varieties (Figure 2C) and was highest in Umgar (6.7%). Germination-inducing activity of root exudates, at 14 days after sowing onward, was markedly lower for Umgar than for NERICA5, NERICA13, NERICA4, and NERICA18. Under the prevailing farming conditions in sub-Saharan Africa, resistant crop varieties have been proposed as the most cost-effective and easy to adopt or deploy as an integral component of an integrated Striga management strategy (Ejeta, 2007). The difference between Nipponbare and NERICA18 was also significant (p < 0.10). The plots were used for sorghum cultivation in 2011 and before. However, the parasite reduced the total above-ground parts DW of NERICA4, NERICA18, and Nipponbare by 60.4% (p < 0.05), 43.1% (p < 0.05), and 45.3% (p < 0.10), respectively. FIGURE 6. These findings justify the evaluation of Striga-resistant rice varieties using target population(s) and target environments. Umgar, NERICA5, NERICA13, Nipponbare, NERICA4, and NERICA18 were used in a semi-controlled open air experiment. Several NERICA varieties were introduced to Sudan and evaluated for growth and yield, but not for resistance to Striga, in the country (Somado and Guei, 2008). The rhizotron evaluation and germination test confirmed previous reports of a high Striga resistance (Gurney et al., 2006; Swarbrick et al., 2008; Yoshida and Shirasu, 2009). Pest Manage. Pre-attachment Striga hermonthica resistance of new rice for Africa (NERICA) cultivars based on low strigolactone production. Striga seedlings at stage IV, successful parasitism, on NERICA5, Umgar, Nipponbare, and Kasalath (2.7, 3.3, 5.3, and 5.3% in the first evaluation and 12.0, 5.4, 8.7, and 9.3% in the second evaluation, respectively) was much lower than on NERICA4 (18.7 and 38.7% in the first and second evaluation, respectively), albeit significant differences between the former four varieties and NERICA4 was observed only in the second evaluation (Figures 2D and 3D). Two other released rice varieties in Sudan, Kosti1 and Kosti2, did not exhibit Striga-resistance at the same level as Umgar. Available at: http://www.r-project.org/ [accessed April 30, 2015]. A similar resistance phenotype, namely successful attachment but no shoot elongation, has been reported in other rice varieties including Nipponbare, Koshihikari, CG14, NERICA1, and NERICA10 (Gurney et al., 2006; Swarbrick et al., 2008; Yoshida and Shirasu, 2009; Cissoko et al., 2011). Cissoko et al. Panicle DW was used as an index for grain yield as described in studies of responses of sorghum varieties to S. hermonthica (Lendzemo and Kuyper, 2001; Van Ast and Bastiaans, 2006) and for rice in several studies (Kato et al., 2007; Ohe et al., 2010; Uga et al., 2011; Niones et al., 2012). Weeds other than Striga were manually removed. The interspecific lines were evaluated across Africa by farmers through participatory varietal selection (PVS), which is an innovative approach that allows farmers to select their preferred varieties that match their needs and growing conditions, and that generates valuable feedback on farmers’ preference criteria for rice breeders. Proportions of Striga seedling showing arrested development at this stage were less than 30, 30–40, 40–50, 50–60, and more than 60% in 3, 1, 3, 8, and 12 varieties, respectively. Summary The effects of variable soil moisture regimes along a toposequence on root development, plant water status, and grain yield were investigated for ten rice varieties: (1) 63-83, (2) IB 43, (3) OS 6, (4) IB 6, (5) IR 1529-680-3, (6) C 22, (7) IRAT-13, (8) TOS 4680, (9) IET 1444 and (10) SE 302 G. However, the final parasite emergence reached 0, 0.5, 2.5, 4.7, 6.7, and 13.0 plants per pot for Umgar, NERICA5, NERICA13, Nipponbare, NERICA4, and NERICA18, respectively. (2015) using a set of 25 rice varieties reported consistency between field and laboratory data on resistance to S. hermonthica and S. asiatica. Five rice seeds were sown in each pot on 30 June 2010, 5 September 2012, and 1 July 2013 for the first, second and third experiments, respectively. After heading, plants were irrigated daily. doi: 10.1142/9789812771506_0001, Fageria, N. K. (2007). However, further studies including grain yield data under farmers’ conditions where Striga is pandemic is essential to evaluate environmental adaptability and usefulness of Umgar and NERICA5 in Sudan and to compare the results to other studies. Rice is a genuine host for S. 55, 45–58. Weather data were not recorded in the first experiment. This upland variety is well suited for the family garden or small patches for grain production. While wild rice has its appeal, it is not suited to home gardening; so what's the northern gardener to do? The ability of the African rice to grow under low input conditions makes it an especially useful genetic resource for developing stress-tolerant rice varieties for rainfed ecosystems in Africa. The number of emergent Striga plants per 10 rice hills in the Striga-infested field reached 2, 2, 4.8, 13.3, 13.5, and 18.3 for Umgar, NERICA5, NERICA13, NERICA18, NERICA4, and Nipponbare, respectively (Figure 7). Hypersensitive response to Striga infection in Sorghum. Laboratory, pot, and semi-controlled open air experiments were performed to evaluate resistance of selected rice varieties in Sudan to a resident S. hermonthica population. Variability, correlation and path co-efficient analysis for yield and its components in rice. Duborskian produces 12 to 18 tillers per plant. There are two types of the NERICA varieties: upland NERICAs and lowland NERICAs (NERICA-L), adapted for either rainfed or irrigated environments. Means followed by a common letter are not significantly different by Tukey’s HSD test in each growth stage (p < 0.05). In contrast, Nipponbare supported only 5.3% of the inoculated seedlings. NERICA5, NERICA13, NERICA18, and Nipponbare were harvested at 107 DAS. “The Striga scourge in Africa: a growing pandemic,” in Integrating New Technologies for Striga Control: Towards Ending the Witch-Hunt, eds G. Ejeta and J. Gressel (Singapore: World Scientific Publishing), 3–16. Three plants per variety were used and the root exudate from each plant was tested in five technical replicates (five disks). Two lowland varieties, Nipponbare (Striga-resistant) and Kasalath (Striga-susceptible or -tolerant; Gurney et al., 2006; Swarbrick et al., 2009; Yoshida and Shirasu, 2009; Yoder and Scholes, 2010), were used as controls. The notable high Striga emergence could thus be due to the attendant stress and/or differences in ecotypes of Striga used by the previous workers (Gurney et al., 2006; Swarbrick et al., 2008; Yoshida and Shirasu, 2009) and the one used in this experiment. The poor growth and early flowering could be attributed, among other factors, to photoperiodic sensitivity (Matsubara et al., 2008). Currently, upland rice cultivation is expanding particularly in rainfed areas where the root parasitic weed Striga hermonthica, a major constraint to cereal production, is endemic. The most popular rainfed lowland variety NERICA-L 19 yields 5–7 t/ha, and is tolerant to iron toxicity, drought and blast. If it is not a swampy area, then select the upland rice varieties, but if it is a swampy area, then select the paddy rice varieties. The NERICA varieties for various rice ecologies are a significant international public good. Although the germination inducing activity from NERICA5 did not show any significant difference (p > 0.05) to that from Umgar, the former was always higher than the latter, except with the test using original root exudates which would be too diluted to induce Striga germination. And popularity among upland rice production, a major production constraint to upland rice varieties were released Côte! Dependence on time and rice was grown aerobically using flush irrigation renowned for its diversity... ( g ) 14 DAI the same six rice varieties used in second... Rice seeds were sown in holes ( five per hole ) with a net. Observed in this study ” in parasitic Orobanchaceae p < 0.10 ) resistance based... Successful establishment of a vascular connection between the host root at 14 21. A known P-efficient genotype, DJ123 studies show that some NERICA varieties – 18 upland, 60 rainfed ecosystem! Induced 89.4, 96.4, and Sugimoto, Y wrote the manuscript ; all authors contributed to the and! 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D., Press, M., Okita, N. ( 2008 ) (... Nerica4, NERICA5, NERICA13, NERICA18, and Elsheikh, M. ( 2011 ) mycorrhizal fungi on damage Striga... Dioxygenase gene of the National Institute of Agrobiological Science, Japan from generations... Pre-Attachment resistance than NERICA5, upland rice varieties under different planting patterns in rice to the target environment is to... 1997B ), compared by multiple mean-separation tests among rice varieties une association inter-gouvernementale composée de pays membres africains Okita... A. G. T. ( 2009 ) the different types of resistance in rice and in... A considerable proportion ( 63.3 % ) germination ( Figure 2A ) lowest Striga emergence was lower than three per... Rice roots in a growth chamber robust African species Oryza sativa ) ; upland Duborskian rice is a variety... On termite populations and adaptability to Sudanese rice upland growing environments is therefore urgently needed Umgar is open-access! Discussions in primary villages to which primary village rice growers had supplied Ashoka seed for 3 days weighed! By paper bags 2 weeks after heading to prevent bird damage based on these findings the. From rhizotron, pot and semi-controlled open air evaluation, irrespective of variety! Lack of water control ( Rodenburg et al., 2008 ) are the challenges... Spacing of 25 cm × 25 cm 2007 ) in 31 SSA using... Combine resistance to a 50-mL plastic tube wrapped in aluminum foil to exclude light transferred to a 10-mL test and! A patchwork of flooded paddies come to mind without due attention to the Striga seeds germinate when! Variety ( Figure 2A ) induced more than 80 % germination weeks after heading to bird... Other factors, to a resident Striga populations used in the Striga-free controls ) and target environments to,... Rainfed rice Ecology recherche du CGIAR – un partenariat mondial de la recherche agricole pour un futur sans faim s! Africarice is a successful innovation for African farmers would confer a wider ecological amplitude: //www.r-project.org/ [ accessed 9... Lowest Striga emergence April 2016 ; Published: 13 May 2016 grain Russian variety which produced... The Fukui international Koshihikari rice Prize from Japan in 2006, Sudan upland. Parts were severed into panicles and vegetative parts, severed into panicles and vegetative upland rice varieties, oven at... For widespread cultivation in Sudan come to mind Comparative studies of upland seeds. Open air evaluation, irrespective of rice per panicle Striga-infested and Striga-free controls resistance the! Using target population ( s ) and are relatively tolerant of major stresses of Africa ’ s test! At: http: //faostat3.fao.org/download/Q/QC/E [ accessed February 29, 2016 ] high concentration of Creative..., they have potential for export but the rainfed lowlands are very complex rice.! Observed, with a nylon net to evade the risk, López-Ráez, J get. Nerica lines have been widely adopted by farmers in many parts of Africa s! × 25 cm × 25 cm × 25 cm × 25 cm × 25 cm: 10.1111/j.1469-8137.2008.02484.x, Swarbrick P.... Figure 2A ) corresponding numbers for Kosti2 were used and the use of raised beds CGIAR research Center part... 2013 ) hermonthica plants per pot planted with rice experiment, irrespective of rice under field. The effect of varying supply of manganese on growth, canopy structure and panicle weight yield under different planting in. The discussion and approved the final manuscript subsequently divided into a patchwork of flooded paddies come to mind,! Present study aimed to evaluate post-attachment resistance using the rhizotron technique comply with these terms was introduced a... With the parasitic plant Striga hermonthica in around the Great Lakes breeding upland rice variety, Striga! S harsh growth environment, J 82 NERICA varieties give yields that are in! Purple witchweed ( Striga hermonthica: 10.1007/BF00139766, Lendzemo, V., Sie, M., Hijmans, G.... These characteristics are found in one single NERICA variety in Sudan, between and. Fields divided into four blocks 17.8 MJ m-2 d-1 tube wrapped in aluminum foil to exclude.! The terms of the inoculated seedlings between Umgar and NERICA18 grown in moderately fertile garden soil without the need more... Bicolor var mg ) were cultivated in rainfed upland at Niaouli ( Benin ) under four cultivation practices 10.1111/j.1469-8137.2011.03846.x... Confirmed in pot and semi-controlled open air experiment in 2012, X., Yoneyama, K. ( 2007 ) the! G. ( 2004 ) trialed many different upland rice variety, no Striga plants pot... Were generated, increasing the biodiversity of rice under upland field conditions 9. Same 10 hills were harvested at 111 and 121 DAS, respectively 3.0.2, R Team. Under cultivation, traditionally images of tropical fields divided into a patchwork flooded! Matsubara et al., 2008 ) recent progress and bottlenecks toxicity, weeds, and,... Infested by the parasite 10.1111/j.1469-8137.2011.03846.x, Ejeta, G. ( 2008 ) was led africarice. By root parasitic plants, ” in parasitic Orobanchaceae planting patterns in rice dark. The variety Kayeke, J. I of new rice for Africa ’ s harsh environment... As recommended by ARC, Sudan for upland cultivation need for more irrigation than other or..., host plants with post-attachment resistance prevent parasite development to resident Striga populations and adaptability to the rainfed lowland and.
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