Browsing by Author "Tongoona, P."

Now showing 1 - 4 of 4
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    Combining Ability and Heterosis for Grain Yield and Rust Resistance in Pearl Millet
    (Journal of Agricultural Science, 2016) Lubadde, G.; Tongoona, P.; Derera, J.; Sibiya, J.
    Pearl millet is a dual-purpose crop in semi-arid zones of Uganda. However, no studies have been conducted to determine the gene effects for yield and yield-related traits and rust resistance in these environments; yet this knowledge is important in improving grain yield and rust resistance. A North Carolina II mating design was adopted to study the genetic effects for rust resistance and yield-related traits of improved pearl millet genotypes. The experimental design to study the objectives was alpha in two [locations, seasons and replications]. A higher proportion of general combining ability (GCA) effect was observed for grain yield, days to 50% flowering, days to 50% anthesis, flower-anthesis interval, days to 50% physiological maturity, plant height, total tiller number, number of productive tillers, percentage of productive tillers, panicle area, leaf area, 1000-grain weight, biological yield and harvest index. The specific combining ability (SCA) effect was predominant for area under disease progress curve. Eleven hybrids performed better than the best male parent and five crosses performed better than the best female parent for grain yield while all the fifteen selected best crosses performed better than all parents for area under disease progress curve. Ten crosses were more resistant to rust than the best male parent and all the crosses were more resistant to rust than the female parents. The additive gene action was predominant for grain yield, rust severity at 50% physiological maturity, days to 50% flowering, days to 50% anthesis, total tiller number, percentage of productive tillers, panicle area, 1000-grain weight, biological yield, harvest index and leaf area. High better-parent heterosis was also observed for most traits including grain yield and rust resistance. The traits were also characterized by relatively low levels of narrow sense heritability.
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    Genomics-assisted breeding for boosting crop improvement in pigeon pea (Cajanus cajan)
    (Frontiers in plant science, 2015) Pazhamala, Lekha; Saxena, Rachit K.; Singh, Vikas K.; Sameerkumar, C.V.; Kumar, Vinay; Sinha, Pallavi; Patel, Kishan; Obala, Jimmy; R.Kaoneka, Seleman; Tongoona, P.; Shimelis, Hussein A.; Gangarao, N.V.P.R.; Odeny, Damaris; Rathore, Abhishek; Dharmaraj, P.S.; Yamini, K. N.; Varshney, Rajeev K.
    Pigeon pea is an important pulse crop grown predominantly in the tropical and sub-tropical regions of the world. Although pigeon pea growing area has considerably increased, yield has remained stagnant for the last six decades mainly due to the exposure of the crop to various biotic and abiotic constraints. In addition, low level of genetic variability and limited genomic resources have been serious impediments to pigeon pea crop improvement through modern breeding approaches. In recent years, however, due to the availability of next generation sequencing and high-throughput genotyping technologies, the scenario has changed tremendously. The reduced sequencing costs resulting in the decoding of the pigeon pea genome has led to the development of various genomic resources including molecular markers, transcript sequences and comprehensive genetic maps. Mapping of some important traits including resistance to Fusarium wilt and sterility mosaic disease, fertility restoration, determinacy with other agronomically important traits have paved the way for applying genomics-assisted breeding (GAB) through marker assisted selection as well as genomic selection (GS). This would accelerate the development and improvement of both varieties and hybrids in pigeon pea. Particularly for hybrid breeding programme, mitochondrial genomes of cytoplasmic male sterile (CMS) lines, maintainers and hybrids have been sequenced to identify genes responsible for cytoplasmic male sterility. Furthermore, several diagnostic molecular markers have been developed to assess the purity of commercial hybrids. In summary, pigeon pea has become a genomic resources-rich crop and efforts have already been initiated to integrate these resources in pigeon pea breeding.
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    Production Determinants of the Pearl Millet Cropping System in Uganda and Implications to Productivity
    (2016) Lubadde, G.; Tongoona, P.; Derera, J.; Sibiya, J.
    Pearl millet is an important crop for people living in semi-arid areas in Uganda but not much is known about its production environment. A survey was conducted in eastern and northern regions of Uganda to characterise the pearl millet cropping system and to identify the most important production determinants. Using questionnaires, data was collected from 160 households through face-to-face interviews with the respondents. Results showed that pearl millet was mainly grown for food and source of income. The production environment was low input as farmers planted unimproved genotypes, used no artificial chemicals or manure, and had minimal access to financial credit and agricultural trainings or extension services. Planting was done in the second rains with no optimal use of important resources like family labour and seed due to seed broadcasting. Farmers desired genotypes with traits such as; stay green, being tall, high tillering, high yield, early maturity and being ergot resistant. The most important constraints were ergot and rust diseases susceptibility, low yield, low tillering, late maturity, sterile panicles, rodents, moulds/rotting and insect pests; while lack of market, low prices and price fluctuation were the important market constraints. Results further showed that farmers lacked knowledge about the common diseases like rust and ergot. The area planted, spouse age and years of pearl millet cultivation were the important factors enhancing production while age of household head, amount of seed planted and distance to the market negatively affected grain yield.
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    Response of locally adapted pearl millet populations to s1 progeny recurrent selection for grain yield and resistance to rust
    (African Crop Science Journal, 2016) Lubadde, G.; Tongoona, P.; Derera, J.; Sibiya, J.
    In the semi-arid zones of Uganda, pearl millet (Pennisetum glaucum (L.) R. Br.) is mainly grown for food and income; but rust (Puccinia substriata var indica (L.) R. Br.) is the main foliar constraint lowering yield. The objective of the study was to genetically improve grain yield and rust resistance of two locally adapted populations (Lam and Omoda), through two cycles of modified phenotypic S1 progeny recurrent selection. Treatments included three cycles of two locally adapted pearl millet populations, evaluated at three locations. Significant net genetic gain for grain yield (72 and 36%) were achieved in Lam and Omoda populations, respectively. This led to grain yield of 1,047 from 611 kg ha-1 in Lam population and 943 from 693 kg ha-1 in Omoda population. Significant improvement in rust resistance was achieved in the two populations, with a net genetic gain of -55 and -71% in Lam and Omoda populations, respectively. Rust severity reduced from 30 to 14% in Lam population and from 57 to 17% in Omoda population. Net positive genetic gains of 68 and 8% were also achieved for 1000- grain weight in Lam and Omoda, respectively. Traits with a net negative genetic gain in both populations were days to 50% flowering, days to 50% anthesis, days to 50% physiological maturity, flower-anthesis interval, plant height and leaf area.