scholarly journals Irrigated and Rain-Fed Lowland Rice Breeding in Uganda: A Review

2021 ◽  
Author(s):  
Jimmy Lamo ◽  
David Ochan ◽  
Desta Abebe ◽  
Zelalem Zewdu Ayalew ◽  
Anna Mlaki ◽  
...  
Keyword(s):  
Rice Blast ◽  
Amylose Content ◽  
Second Phase ◽  
Rice Yellow Mottle Virus ◽  
Rice Varieties ◽  
Breeding Lines ◽  
Third Phase ◽  
Yellow Mottle ◽  
Breeding Efficiency ◽  
Selection Of

Since introduction of rice into Uganda in 1904, improvement of the irrigated and rain-fed lowland types was undertaken to address a number of production and quality constraints in three consecutive and overlapping phases. The initial phase was achieved through evaluation of introduction, selection of promising lines and subsequent release of the selected lines for production by the farmers. In the second phase, genetic potential of traits and characteristics of interest were analyzed and used to guide selection of suitable parents for hybridization and the third phase employed genotyping approach in screening and selection of the parental lines and the segregating populations to enhance the breeding efficiency for the traits of importance. Simultaneously, the key production constraints addressed included resistance to rice yellow mottle virus (RYMV), rice blast, bacterial leaf blight and narrow leaf spot diseases as well as submergence tolerance and cold tolerance. The quality traits considered for the improvement alongside the grain yield parameters were the grain aroma, amylose content, shape and size. These interventions have resulted into release and wide adoption of seven rice varieties in Uganda besides several breeding lines which have informally diffused into different major rice production agro-ecology. Subsequently, it can be concluded that a substantially strong and functional breeding platform for rice in Uganda has been established.

The needs of siblings of children with a life-threatening illness, part 1: Conceptualization and development of a measure

2017 ◽  
Vol 15 (6) ◽  
pp. 644-664 ◽  
Author(s):  
Marianne Olivier-D'Avignon ◽  
Serge Dumont ◽  
Pierre Valois ◽  
S. Robin Cohen
Keyword(s):  
Qualitative Methodology ◽  
Critically Ill Children ◽  
Second Phase ◽  
Difficult Situation ◽  
Promising Tool ◽  
Third Phase ◽  
Life Threatening Illness ◽  
Preliminary Version ◽  
Life Threatening ◽  
Selection Of

ABSTRACTObjective:The presence of a child afflicted with a life-threatening illness is a difficult situation for the child's siblings, especially when their own needs are left unmet. The present article describes the first three phases of research involved in the conceptualization, development, and content validation of an initial version of the Inventaire des Besoins de la Fratrie d'Enfants Malades Sévèrement (IBesFEMS) [Needs Inventory for Siblings of Critically ill Children].Method:The first phase of the development of this instrument was conducted using qualitative methodology (focus groups: 6 siblings, 8 parents). The second phase consisted of validating the content of a pool of items developed according to the needs identified in the first phase. Some 21 participants (3 psychometricians, 3 researchers, 9 clinicians, and 6 siblings) evaluated each item for relevance and clarity. Finally, during the third phase, the acceptability and administration procedures of the preliminary version of the instrument were assessed qualitatively by five siblings.Results:The first phase led to production of a typology made up of 43 needs in 10 different environments. The second phase allowed for selection of the items that were clearest and most relevant, based on expert opinion. This procedure gave rise to a first version of the IBesFEMS, which consisted of 48 items.Significance of results:The IBesFEMS appears to be a promising tool for specifically assessing the needs of the adolescent siblings of seriously ill children.

Ciri Morfologi, Fisiko-Kimia dan Kerintangan Dua Titisan Padi Kemandulan Jantan Sitoplasma (CMS) Baru

2014 ◽  
Vol 70 (6) ◽  
Author(s):  
Elixon Sunian ◽  
Mohd. Solihen Jamal ◽  
Asfaliza Ramli ◽  
Othman Omar ◽  
Habibbudin Hashim ◽  
...  
Keyword(s):  
Amylose Content ◽  
Brown Planthopper ◽  
Blast Disease ◽  
Male Sterile ◽  
Rice Varieties ◽  
Gel Consistency ◽  
Moderately Resistant ◽  
Maturation Age ◽  
B Lines ◽  
Selection Of

CMS (cytoplasmic male sterile) line is one of the most important hybrid parents in hybrid rice production technology using Three-Line systems. Test-crosses for selection of candidate local maintainer lines were conducted using 24 rice varieties and two CMS-WA (wild abortive) lines IR78374A/B and 1A/B. The F1 of the two combinations, namely IR78374A/P519 and 1A/MR243 had less than 10% spikelet fertility (6.4 and 7.2%, respectively), indicated that P519 and MR243 are partially maintainers and could be used for the development of new locally adapted CMS lines. As a results, two CMS lines, namely 0025A/B and 0047A/B were generated after 5 to 6 successive backcrossing of IR78374A with P519 and 1A with MR243. The CMS 0025A/B and 0047A/B lines had maturation age which is comparable to other commonly grown inbred varieties. The percentage of stigma exertion rate for CMS 0025A/B and 0047A/B were 17.9 and 21.3%, respectively, lower than that of IR78374A/B (43.2%). Both showed poor out-crossing rate. CMS 0025A/B and 0047A/B are classified as long and slender grain. They had intermediate amylose content. Their gel consistency was hard, comparable to that of MR263 (medium).  CMS 0025A/B and 0047A/B lines were also moderately resistant to foliar blast disease and brown planthopper infestation.

scholarly journals CORRELATION ANALYSIS OF AGRONOMIC CHARACTERS AND GRAIN YIELD OF RICE FOR TIDAL SWAMP AREAS

2013 ◽  
Vol 11 (1) ◽  
pp. 11 ◽  
Author(s):  
Aris Hairmansis ◽  
Bambang Kustianto ◽  
Suwarno Suwarno
Keyword(s):  
Grain Yield ◽  
Direct Effect ◽  
Spikelet Fertility ◽  
Rice Grain ◽  
Agronomic Characters ◽  
Rice Varieties ◽  
Breeding Lines ◽  
Tidal Swamp ◽  
Positive Direct ◽  
Selection Of

<p>Development of rice varieties for tidal swamp areas is emphasized on the improvement of rice yield potential in specific environment. However, grain yield is a complex trait and highly dependent on the other agronomic characters; while information related to the relationship between agronomic characters and grain yield in the breeding program particularly for tidal swamp areas is very limited. The objective of this study was to investigate relationship between agronomic characters and grain yield of rice as a basis for selection of high yielding rice varieties for tidal swamp areas. Agronomic characters and grain yield of nine advanced rice breeding lines and two rice varieties were evaluated in a series of experiments in tidal swamp areas, Karang Agung Ulu Village, Banyuasin, South Sumatra, for four cropping seasons in dry season (DS) 2005, wet season (WS) 2005/2006, DS 2006, and DS 2007. Result from path analysis revealed that the following characters had positive direct effect on grain yield, i.e. number of productive tillers per hill (p = 0.356), number of filled grains per panicle (p = 0.544), and spikelet fertility (p = 0.215). Plant height had negative direct effect (p = -0.332) on grain yield, while maturity, number of spikelets per panicle, and 1000-grain weight showed negligible effect on rice grain yield. Present study suggests that indirect selection of high yielding tidal swamp rice can be done by selecting breeding lines which have many product tive tillers, dense filled grains, and high spikelet fertility.</p>

scholarly journals Insights Into Natural Genetic Resistance to Rice Yellow Mottle Virus and Implications on Breeding for Durable Resistance

2021 ◽  
Vol 12 ◽  
Author(s):  
Patrick J. Odongo ◽  
Geoffrey Onaga ◽  
Oliver Ricardo ◽  
Keiko T. Natsuaki ◽  
Titus Alicai ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Durable Resistance ◽  
Translation Initiation Factor ◽  
Sub Saharan Africa ◽  
Initiation Factor ◽  
Mottle Virus ◽  
Rice Yellow Mottle Virus ◽  
Rice Varieties ◽  
Biotic Factor ◽  
Yellow Mottle

Rice is the main food crop for people in low- and lower-middle-income countries in Asia and sub-Saharan Africa (SSA). Since 1982, there has been a significant increase in the demand for rice in SSA, and its growing importance is reflected in the national strategic food security plans of several countries in the region. However, several abiotic and biotic factors undermine efforts to meet this demand. Rice yellow mottle virus (RYMV) caused by Solemoviridae is a major biotic factor affecting rice production and continues to be an important pathogen in SSA. To date, six pathogenic strains have been reported. RYMV infects rice plants through wounds and rice feeding vectors. Once inside the plant cells, viral genome-linked protein is required to bind to the rice translation initiation factor [eIF(iso)4G1] for a compatible interaction. The development of resistant cultivars that can interrupt this interaction is the most effective method to manage this disease. Three resistance genes are recognized to limit RYMV virulence in rice, some of which have nonsynonymous single mutations or short deletions in the core domain of eIF(iso)4G1 that impair viral host interaction. However, deployment of these resistance genes using conventional methods has proved slow and tedious. Molecular approaches are expected to be an alternative to facilitate gene introgression and/or pyramiding and rapid deployment of these resistance genes into elite cultivars. In this review, we summarize the knowledge on molecular genetics of RYMV-rice interaction, with emphasis on host plant resistance. In addition, we provide strategies for sustainable utilization of the novel resistant sources. This knowledge is expected to guide breeding programs in the development and deployment of RYMV resistant rice varieties.

scholarly journals First Report of Rice yellow mottle virus in Rice in The Gambia

Plant Disease ◽  
2008 ◽  
Vol 92 (2) ◽  
pp. 316-316 ◽  
Author(s):  
Y. Sere ◽  
F. Sorho ◽  
A. Onasanya ◽  
L. Jobe ◽  
S. Darboe ◽  
...  
Keyword(s):  
Coat Protein ◽  
Phylogenetic Reconstruction ◽  
The Gambia ◽  
Eastern Africa ◽  
Mottle Virus ◽  
Rice Yellow Mottle Virus ◽  
Leaf Extracts ◽  
Rice Varieties ◽  
Embl Accession ◽  
Yellow Mottle

Rice yellow mottle virus (RYMV) of the genus Sobemovirus is a major biotic constraint to rice (Oryza sativa) production in Africa. First reported in Kenya during 1966, RYMV was later found in most countries in Africa where rice is grown (1). In countries in westernmost Africa (The Gambia, Guinea-Bissau, Mauritania, and Senegal), plants with leaf yellowing and mottling symptoms were observed, but RYMV was never isolated. Rice is the staple food in The Gambia. In 2006, four samples were collected from local rice varieties in the Kuntaur Region in the center of The Gambia. Mechanical inoculation with leaf extracts from all samples caused typical yellow mottle symptoms on the susceptible rice varieties BG90-2, Bouaké 189, and IR64. RYMV was detected in the four samples collected by ELISA with polyclonal antisera (2). The 720-nt coat protein gene was amplified for each isolate by reverse-transcriptase-PCR with primers 5′-CAAAGATGGCCAGGAA-3′ (sense) and 5′-CTCCCCCACCCATCCCGAGAATT-3′ (antisense) (2). The RT-PCR products were directly sequenced (EMBL Accession Nos. AM765810, AM765811, AM765812, and AM765813) and then aligned using ClustalW with a pool of RYMV coat protein sequences from West African isolates (EMBL Accession Nos. AJ279905, AJ279901, AJ885137, AJ885124, and AJ279935). Phylogenetic reconstruction by maximum-likelihood with PAUP indicated that the isolates from The Gambia formed a monophyletic group with over 97% nucleotide identity and are closely related to isolates of other countries in West Africa (Burkina Faso, Côte d'Ivoire, Guinea, Mali, and Sierra-Leone) with 91 to 94% identity. Detection of RYMV in The Gambia indicates that RYMV is present in westernmost Africa, which is referred to as the ‘rice belt’ of Africa, and shows that RYMV is widely distributed from eastern Africa (Tanzania) to the western part of the continent. References: (1) N. K. Kouassi et al. Plant Dis. 89:124, 2005. (2) A. Pinel et al. Arch. Virol. 145:1621, 2000.

scholarly journals CORRELATION ANALYSIS OF AGRONOMIC CHARACTERS AND GRAIN YIELD OF RICE FOR TIDAL SWAMP AREAS

2013 ◽  
Vol 11 (1) ◽  
pp. 11 ◽  
Author(s):  
Aris Hairmansis ◽  
Bambang Kustianto ◽  
Suwarno Suwarno
Keyword(s):  
Grain Yield ◽  
Direct Effect ◽  
Spikelet Fertility ◽  
Rice Grain ◽  
Agronomic Characters ◽  
Rice Varieties ◽  
Breeding Lines ◽  
Tidal Swamp ◽  
Positive Direct ◽  
Selection Of

<p>Development of rice varieties for tidal swamp areas is emphasized on the improvement of rice yield potential in specific environment. However, grain yield is a complex trait and highly dependent on the other agronomic characters; while information related to the relationship between agronomic characters and grain yield in the breeding program particularly for tidal swamp areas is very limited. The objective of this study was to investigate relationship between agronomic characters and grain yield of rice as a basis for selection of high yielding rice varieties for tidal swamp areas. Agronomic characters and grain yield of nine advanced rice breeding lines and two rice varieties were evaluated in a series of experiments in tidal swamp areas, Karang Agung Ulu Village, Banyuasin, South Sumatra, for four cropping seasons in dry season (DS) 2005, wet season (WS) 2005/2006, DS 2006, and DS 2007. Result from path analysis revealed that the following characters had positive direct effect on grain yield, i.e. number of productive tillers per hill (p = 0.356), number of filled grains per panicle (p = 0.544), and spikelet fertility (p = 0.215). Plant height had negative direct effect (p = -0.332) on grain yield, while maturity, number of spikelets per panicle, and 1000-grain weight showed negligible effect on rice grain yield. Present study suggests that indirect selection of high yielding tidal swamp rice can be done by selecting breeding lines which have many product tive tillers, dense filled grains, and high spikelet fertility.</p>

Resistance to rice yellow mottle virus (RYMV) in cultivated African rice varieties containing RYMV transgenes

10.1038/10917 ◽  
1999 ◽  
Vol 17 (7) ◽  
pp. 702-707 ◽  
Author(s):  
Yvonne M. Pinto ◽  
Rosan A. Kok ◽  
David C. Baulcombe
Keyword(s):  
Mottle Virus ◽  
Rice Yellow Mottle Virus ◽  
Rice Varieties ◽  
African Rice ◽  
Yellow Mottle
Sign in / Sign up

Export Citation Format

Share Document