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A very high consumption growth rate has made rice one of the most important crops in Africa, but Africa's rice production growth rate is too low to match the consumption trend. A strong thrust is needed to boost rice production and productivity in Africa, especially in eastern and southern Africa (ESA), where large suitable land areas and resources with a congenial environment are available. Rice breeding activities in ESA, specifically for rainfed lowlands and irrigated ecosystems that have maximum area, did not receive enough attention in the past and hence lag behind in the development of appropriate high-yielding varieties. A poor rice variety development program for rainfed lowlands and irrigated areas was also marred by poor capacity, poor infrastructure, and a lack of proper policy support. This paper discusses the current issues related to the rice breeding scenario and the initiation of breeding support by CGIAR institutes such as IRRI in ESA. [ABSTRACT FROM AUTHOR]

Genetic variability is the key for the development of new genotypes with desired combination of traits. Many times, the traditional donors for tolerance to stresses such as salinity look similar but differ in their response to the stresses. Molecular characterization of the genotypes gives precise information about the extent of genetic diversity which helps in the development of an appropriate breeding strategy. One hundred polymorphic SSR markers were used to characterize 21 rice genotypes. These genotypes comprised of nine salt tolerant genotypes including five Pokkali accessions. The materials also included two improved varieties with a major QTL for submergence (Sub1) in Swarna background, i.e. IR82810-407 and IR82809-237. The rest were popular or moderately salt tolerant rice varieties of Bangladesh, India, International Rice Research Institute (IRRI), or Philippines origin. The highest number of alleles (12) were found for RM418 followed by RM10793 (11), RM3412, RM400, and RM26809 (10). The highest PIC value (0.86) was found for RM10793 followed by RM418 and RM3412 (0.85), RM26809, RM490 and RM287 (0.84), RM16 (0.83), RM493, RM562, and RM253 (0.82). These suggested their greater usefulness for characterizing rice varieties. Pokkali (Acc. No. 28609) and PSBRc82 were found to be the most genetically distant (78.65%) varieties. The Swarna + Sub1 genotypes (IR82810-407 and IR82809-237) had the same genetic background; hence, they had highest genetic similarity between them (90%) and also with Swarna (>70%). Two main distinct clusters/groups were identified from cluster analysis. One cluster consists of mostly improved and adapted genotypes while the second cluster had mostly salt tolerant donors with few exceptions. The study suggests the recombination strategy for the effective breeding program to enhance the level of salt tolerance and also to broaden the genetic base for wider adaptability. [ABSTRACT FROM AUTHOR]

The participatory varietal selection approach is the first attempt in Myanmar through collaborative efforts from IRRI-LIFT. Sixteen and 12 varieties/lines were evaluated in the monsoon and dry season, respectively, through PVS in different villages in three townships of the Ayeyarwady Delta. Four varieties/lines (Saltol Sin Thwe Latt, Shwe Pyi Htay, Sin Thu Kha, and Shwe Ta Soke) in the wet season of 2012 and four varieties/lines (IR10T107, IR10T108, IR10T111, and CSR36) in the dry season of 2012-13 were selected by farmers through preference analysis, grain yield and sensory evaluation. After field evaluation, Saltol Sin Thwe Latt was released as a variety in Myanmar. Farmer-managed trials (baby trials) were carried out using the selected lines from the wet season. Based on baby trials in the 2013 wet season, Saltol Sin Thwe Latt (Saltol STL) and Sin Thu Kha (STK) were the first and second most adapted and stable high-yielding varieties for three townships in the Ayeyarwady Delta. PVS has the potential to become one of the best approaches in research for developing a variety based on farmers choice and enhancing their productivity and dissemination, especially in the Ayeyarwady Delta, Myanmar, to help resourcepoor farmers in obtaining easy access to rice-based technology for improving their livelihood. [ABSTRACT FROM AUTHOR]

Flash flooding is one of the most important yield limiting factors of rice in South Asia, particularly in eastern India and Bangladesh. Productivity of flood-prone areas is not only low but also unstable. Swarna is the most popular variety of India and Bangladesh, and covers about 6 million ha in these two countries. This was the first variety for which the flash-flood tolerance gene (SUB1A) was introgressed using marker assisted backcrossing. Later, this gene was introgressed into 4 more mega rice varieties of South Asia (Samba Mahsuri, IR64, CR1009 of India and BR11 of Bangladesh). The Sub1 varieties, particularly Swarna-Sub1, in India, Bangladesh and Nepal and BR11-Sub1 in Bangladesh, showed excellent performance. They offered a yield advantage of up to 1 to 3 t/ha, depending upon the duration of submergence, and were as good or better than original varieties, when there were no floods. Swarna-Sub1 was released for cultivation in India in 2009; Swarna-Sub1 and BR11-Sub1 in Bangladesh in 2010 and Samba Mahsuri-Sub1 and Swarna-Sub1 in Nepal in 2011. Due to their excellent performance in farmers'fields and the proactive role played by the Bill and Melinda Gates Foundation funded 'Stress Tolerant Rice for Africa and South Asia (STRASA) program, these varieties have been widely promoted and adopted by farmers. Key aspects of the successful adoption by farmers was due to strong support and commitment from national systems for varietal release, development of promotion and policy strategies and guidelines, and the development of an extensive network of the partners from public and private sectors, non-government organizations (NGOs), farmers organizations for seed multiplication and dissemination, and innovative interventions such as pre-release seed multiplication and dissemination, awareness creation, and post-release targeted dissemination. These Sub1 varieties are now spreading at an unprecedented pace in India, Bangladesh and Nepal, and are expected to cover >5 million ha by 2014 in these three countries. These Sub1 varieties also encourage farmers to use more inputs. Thus, they have the potential to usher a second green revolution in the flood-prone rainfed rice areas, which did not benefit from the first green revolution initiated during the mid-sixties. [ABSTRACT FROM AUTHOR]

Twenty four isolates of Fusarium oxysporum f. sp. lentis (Fol,) collected from different lentil growing areas of the Gangetic plain showed variation with respect to cultural and morphological characters. The extent of genetic diversity was evaluated using a set of 40 RAPD primers and 12 SSR primer pairs, out of which 25 RAPD primers and 9 SSR primer pairs revealed polymorphisms among the isolates. A total of 217 polymorphic fragments for the RAPD primers and 22 for the SSR primers were scored. Genetic similarity between each the isolates was calculated using the Jaccard similarity coefficient and cluster analysis was used to generate a dendrogram showing relationship between them. The isolates could be grouped into two subpopulations based on RAPD and SSR analysis. Results obtained indicate that there is little genetic variability among a subpopulation of Fol as identified by RAPD and SSR markers. Also, results indicated that the Fol isolates differ in their aggressiveness on the susceptible lines and that there is no apparent correlation between geographical origin and aggressiveness of isolates. [ABSTRACT FROM AUTHOR]