scholarly journals Significant progressive heterobeltiosis in banana crossbreeding

2020 ◽  
Author(s):  
Michael Batte ◽  
Moses Nyine ◽  
Brigitte Uwimana ◽  
Rony Swennen ◽  
Violet Akech ◽  
...  
Keyword(s):  
Genetic Distance ◽  
Yield Potential ◽  
Food Crops ◽  
East African ◽  
Plant Stature ◽  
Breeding Efficiency ◽  
Cooking Banana ◽  
Tetraploid Parent ◽  
Positive Significant Correlation ◽  
Over Time

Abstract Background: Heterobeltiosis is the phenomenon when the hybrid’s performance is superior to its best performing parent. Banana ( Musa spp. AAA) breeding is a tedious, time-consuming process, taking up to two decades to develop a consumer acceptable hybrid. Exploiting heterobeltiosis in banana breeding will help to select breeding material with high complementarity, thus increasing banana breeding efficiency. The aim of this study was therefore to determine and document the level of heterobeltiosis of bunch weight and plant stature in the East African highland bananas, in order to identify potential parents that can be used to produce offspring with desired bunch weight and stature after a few crosses.Results: This research found significant progressive heterobeltiosis in cross-bred ‘Matooke’ (highland cooking) banana hybrids, also known as NARITAs, when grown together across years with their parents and grandparents in Uganda. Most (all except 4) NARITAs exhibited positive heterobeltiosis for bunch weight, whereas slightly more than half of them had negative heterobeltiosis for stature. The secondary triploid NARITA 17 had the highest heterobeltiosis for bunch weight: 249% versus its matooke grandparent and 136% against its primary tetraploid parent. Broad sense heritability (across three cropping cycles) for yield potential and bunch weight were high (0.84 and 0.76 respectively), while that of plant stature was very low (0.0035). There was a positive significant correlation ( P < 0.05) between grandparent heterobeltiosis for bunch weight and genetic distance between parents (r = 0.39, P = 0.036), bunch weight (r = 0.7, P < 0.001), plant stature (r = 0.38, P = 0.033) and yield potential (r = 0.59, P < 0.001). Grandparent heterobeltiosis for plant stature was significantly, but negatively, correlated to the genetic distance between parents (r = -0.6, P < 0.001).Conclusions: Such significant heterobeltiosis exhibited for bunch weight is to our knowledge the largest among main food crops. Since bananas are vegetatively propagated, the effect of heterobeltiosis is easily fixed in the hybrids and will not be lost over time after the release and further commercialization of these hybrids.

scholarly journals Significant progressive heterobeltiosis in banana crossbreeding

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Michael Batte ◽  
Moses Nyine ◽  
Brigitte Uwimana ◽  
Rony Swennen ◽  
Violet Akech ◽  
...  
Keyword(s):  
Genetic Distance ◽  
Yield Potential ◽  
Food Crops ◽  
East African ◽  
Plant Stature ◽  
Breeding Efficiency ◽  
Cooking Banana ◽  
Tetraploid Parent ◽  
Positive Significant Correlation ◽  
Over Time

Abstract Background Heterobeltiosis is the phenomenon when the hybrid’s performance is superior to its best performing parent. Banana (Musa spp. AAA) breeding is a tedious, time-consuming process, taking up to two decades to develop a consumer acceptable hybrid. Exploiting heterobeltiosis in banana breeding will help to select breeding material with high complementarity, thus increasing banana breeding efficiency. The aim of this study was therefore to determine and document the level of heterobeltiosis of bunch weight and plant stature in the East African highland bananas, in order to identify potential parents that can be used to produce offspring with desired bunch weight and stature after a few crosses. Results This research found significant progressive heterobeltiosis in cross-bred ‘Matooke’ (highland cooking) banana hybrids, also known as NARITAs, when grown together across years with their parents and grandparents in Uganda. Most (all except 4) NARITAs exhibited positive heterobeltiosis for bunch weight, whereas slightly more than half of them had negative heterobeltiosis for stature. The secondary triploid NARITA 17 had the highest heterobeltiosis for bunch weight: 249% versus its ‘Matooke’ grandparent and 136% against its primary tetraploid parent. Broad sense heritability (across three cropping cycles) for yield potential and bunch weight were high (0.84 and 0.76 respectively), while that of plant stature was very low (0.0035). There was a positive significant correlation (P < 0.05) between grandparent heterobeltiosis for bunch weight and genetic distance between parents (r = 0.39, P = 0.036), bunch weight (r = 0.7, P < 0.001), plant stature (r = 0.38, P = 0.033) and yield potential (r = 0.59, P < 0.001). Grandparent heterobeltiosis for plant stature was significantly, but negatively, correlated to the genetic distance between parents (r = − 0.6, P < 0.001). Conclusions Such significant heterobeltiosis exhibited for bunch weight is to our knowledge the largest among main food crops. Since bananas are vegetatively propagated, the effect of heterobeltiosis is easily fixed in the hybrids and will not be lost over time after the release and further commercialization of these hybrids.

scholarly journals Significant Progressive Heterobeltiosis in Banana Crossbreeding

2020 ◽  
Author(s):  
Michael Batte ◽  
Moses Nyine ◽  
Brigitte Uwimana ◽  
Rony Swennen ◽  
Violet Akech ◽  
...  
Keyword(s):  
Genetic Distance ◽  
Yield Potential ◽  
Food Crops ◽  
East African ◽  
Main Food ◽  
Musa Spp ◽  
Plant Stature ◽  
Breeding Efficiency ◽  
Positive Significant Correlation ◽  
Over Time

Abstract Background: Heterobeltiosis is the phenomenon when the hybrid’s performance is superior to its best performing parent. Banana ( Musa spp. AAA) breeding is a tedious, time-consuming process, taking up to two decades to develop a consumer acceptable hybrid. Exploiting heterobeltiosis in banana breeding will contribute to selecting breeding material with high compatibility, thus increasing banana breeding efficiency. The aim of this study was therefore to determine and document the level of heterobeltiosis of bunch weight and plant stature in the East African highland bananas, in order to identify potential parents that can be used to produce offspring with desired bunch weight and stature after a few crosses. Results: This study found significant progressive heterobeltiosis in cross-bred ‘Matooke’ banana hybrids, also known as NARITAs, when grown together across years with their parents and grandparents in Uganda. All NARITAs exhibited positive heterobeltiosis for bunch weight, whereas half of them had negative heterobeltiosis for stature. NARITA 17 had the highest heterobeltiosis for bunch weight (248.7%), followed by 26666S-1 (229.3%), while the lowest was noted in NARITA 19 (1.2%). Heritability for yield potential and bunch weight were high (0.84 and 0.76 respectively), while that of plant stature was very low (0.0035). There was a positive significant correlation ( P < 0.05) between grandparent heterobeltiosis for bunch weight and genetic distance between NARITAs’ parents (r = 0.39, P = 0.036), bunch weight (r = 0.7, P < 0.001), plant stature (r = 0.38, P = 0.033) and yield potential (r = 0.59, P = 0.0004). Grandparent heterobeltiosis for plant stature was significantly, but negatively, correlated to the genetic distance between NARITA parents (r = -0.6, P = 0.0004). Conclusions: Such significant heterobeltiosis exhibited for bunch weight is to our knowledge the largest among main food crops. Since bananas are vegetatively propagated, the effect of heterobeltiosis is easily fixed in the hybrids and will not be lost over time after the release and further commercialization of these hybrids.

scholarly journals Land Policy and Food Prices: Evidence from a Land Consolidation Program in Rwanda

2021 ◽  
Vol 19 (1) ◽  
pp. 63-73
Author(s):  
Aimable Nsabimana ◽  
Fidele Niyitanga ◽  
Dave D. Weatherspoon ◽  
Anwar Naseem
Keyword(s):  
Food Prices ◽  
Land Policy ◽  
Land Consolidation ◽  
Easy Access ◽  
Food Crops ◽  
White Potato ◽  
Before And After ◽  
Price Differences ◽  
The Impact ◽  
Over Time

Abstract Rwanda’s “Crop Intensification Program (CIP)” is primarily a land consolidation program aimed at improving agricultural productivity and food security. The program, which began in 2007, focuses on monocropping and commercialization of six priority crops: maize, wheat, rice, white potato, beans, and cassava. CIP has facilitated easy access to improved seed stocks, fertilizer, extension services, and postharvest handling and storage services. Although studies have documented the impact of CIP on changes in farm yield, incomes, and productivity, less is known about its impact on food prices. In this study, we examine the crop-food price differences in intensive monocropped CIP and non-intensive monocropped CIP zones in Rwanda. Specifically, the study evaluates price variations of beans and maize along with complementary food crops in intensive and non-intensive monocropped zones before and after the introduction of the CIP policy. We find that the CIP policy is not associated with differences in CIP crop prices between the intensive and non-intensive monocropped zones. Over time, prices increased for CIP crops but generally, the crop prices in the two zones were cointegrated. Prices for non-CIP crops in the two different zones did show price differentials prior to the implementation of CIP, with the prices in intensive monocropped zones being greater than in the non-intensive monocropped zones. Moreover, the prices in intensive areas are cointegrated with prices in non-intensive areas for maize and beans and these prices are converging. This indicates that farmers who intensively produced one CIP crop were able to go to the market and purchase other food crops and that price differences between zones have decreased over time, potentially making the CIP intensive farmers better off.

scholarly journals Modeling neutral viral mutations in the spread of SARS-CoV-2 epidemics

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0255438
Author(s):  
Vitor M. Marquioni ◽  
Marcus A. M. de Aguiar
Keyword(s):  
Population Genetics ◽  
Analytical Solution ◽  
Genetic Distance ◽  
Mean Field ◽  
Neutral Evolution ◽  
Genetic Evolution ◽  
Epidemic Spreading ◽  
Different Strains ◽  
Over Time ◽  
Good Agreement

Although traditional models of epidemic spreading focus on the number of infected, susceptible and recovered individuals, a lot of attention has been devoted to integrate epidemic models with population genetics. Here we develop an individual-based model for epidemic spreading on networks in which viruses are explicitly represented by finite chains of nucleotides that can mutate inside the host. Under the hypothesis of neutral evolution we compute analytically the average pairwise genetic distance between all infecting viruses over time. We also derive a mean-field version of this equation that can be added directly to compartmental models such as SIR or SEIR to estimate the genetic evolution. We compare our results with the inferred genetic evolution of SARS-CoV-2 at the beginning of the epidemic in China and found good agreement with the analytical solution of our model. Finally, using genetic distance as a proxy for different strains, we use numerical simulations to show that the lower the connectivity between communities, e.g., cities, the higher the probability of reinfection.

Lactation performance of goats and growth rates of kids under different milking and rearing methods in Kenya

1988 ◽  
Vol 46 (2) ◽  
pp. 237-242 ◽  
Author(s):  
F. Ruvuna ◽  
T. C. Cartwright ◽  
H. Blackburn ◽  
M. Okeyo ◽  
S. Chema
Keyword(s):  
Milk Yield ◽  
Growth Rates ◽  
Smallholder Farmers ◽  
Yield Potential ◽  
Lactation Performance ◽  
East African ◽  
Dual Purpose ◽  
Total Milk ◽  
Rearing Methods ◽  
Least Squares Techniques

AbstractTwo experiments were conducted to test different milking procedures for dual-purpose goats that would be suitable for smallholder farmers. In experiment 1, 105 East African and Galla does that kidded to singles were randomly assigned to three treatments: (a) milking in absence of kid and kid sucking residual; (b) milking in presence of kid and kid sucking residual; and (c) milking once a week and kid sucking all milk 6 days of the week. In experiment 2, 45 Galla does that kidded to singles were randomly assigned to three treatments: (a) weigh-suckle-weigh; (b) milking half udder while kid sucking other half and (c) kid sucking all milk in the evening and milking mornings. Measurements of milk yield, milk sucked and weights of kids were taken for 12 weeks of lactation.Results were analysed using least-squares techniques for unequal subclass numbers. Milking in the presence of kids increased does' milk yield. This increase was attributed to the stimulation of milk let-down by the presence of kids. Although this method potentially provided most milk for dairy use, less residual milk was left to sustain growth of kids. Estimates of total milk yield by milking once a week underestimated milk yield potential of the East African and Galla breeds. Results indicated an appropriate method for estimating milk potential should combine both milked and sucked milk measurements. Restricting milk available to the kids reduced their growth rates and thus indirectly affected their maturing rates. No milking procedure proved to be superior all-around for the smallholder for milking goats. To resolve this dilemma, use of an optimizing technique including socio-economic weighting of milk for family use relative to milk for kids was proposed.

scholarly journals Breeding progress for pathogen resistance is a second major driver for yield increase in German winter wheat at contrasting N levels

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Holger Zetzsche ◽  
Wolfgang Friedt ◽  
Frank Ordon
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Fungal Pathogens ◽  
Large Scale ◽  
Pathogen Resistance ◽  
Wheat Breeding ◽  
Yield Potential ◽  
Head Blight ◽  
Wheat Production ◽  
Over Time

AbstractBreeding has substantially increased the genetic yield potential, but fungal pathogens are still major constraints for wheat production. Therefore, breeding success for resistance and its impact on yield were analyzed on a large panel of winter wheat cultivars, representing breeding progress in Germany during the last decades, in large scale field trials under different fungicide and nitrogen treatments. Results revealed a highly significant effect of genotype (G) and year (Y) on resistances and G × Y interactions were significant for all pathogens tested, i.e. leaf rust, strip rust, powdery mildew and Fusarium head blight. N-fertilization significantly increased the susceptibility to biotrophic and hemibiotrophic pathogens. Resistance was significantly improved over time but at different rates for the pathogens. Although the average progress of resistance against each pathogen was higher at the elevated N level in absolute terms, it was very similar at both N levels on a relative basis. Grain yield was increased significantly over time under all treatments but was considerably higher without fungicides particularly at high N-input. Our results strongly indicate that wheat breeding resulted in a substantial increase of grain yield along with a constant improvement of resistance to fungal pathogens, thereby contributing to an environment-friendly and sustainable wheat production.

scholarly journals NC 98-608: MANAGING THE POTENTIAL NEW SWEETPOTATO (Ipomea batatas) CLONE RELEASE

HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 869b-869
Author(s):  
Allan C. Thornton ◽  
Jonathan R. Schultheis
Keyword(s):  
Yield Potential ◽  
Row Spacing ◽  
Harvest Time ◽  
Planting Dates ◽  
Late Planting ◽  
Early Planting ◽  
Ipomea Batatas ◽  
Early Harvest ◽  
Over Time ◽  
Made In

The goal of this research was to determine the effects of in-row spacing and planting time on yield and root grade of NC 98-608 over time. Two plantings were made in two grower locations (four total). An early planting was made 19 and 25 May and a late planting 19 and 24 June. NC 98-608 was evaluated at the following in-row spacings; 23, 31, 38, and 46 cm. `Beauregard' spaced at 23 cm in-row and was used as the standard comparison. Roots were harvested and graded into canner, number one, jumbo and cull grades 90, 105, and 120 days after planting for each of the planting dates and locations. Each grade was weighed. An early planting in late May resulted in roots reaching the highest percentage grade of U.S. number one roots as early as 100 days after planting, while the late planting in June resulted in roots never reaching their full number one yield potential in some cases. For an early harvest after planting (90 days after planting) the 38 cm in-row spacing produced the most marketable number one yields compared with the 23, 31, and 46 cm in-row spacings. For a later harvest time after planting (105 days or later), it appeared as though the 31 cm in-row spacing was the most economical spacing to use. Roots from the early plantings (late May) and finer textured soils appeared to have shorter roots than roots harvested from later plantings (after 15 June) or coarser textured soil. Root shape and yield was more uniform with NC 98-608 than with the Beauregard clone. With yields comparable to Beauregard, the NC 98-608 clone provides an excellent opportunity to produce a quality sweetpotato with consistent shape.

scholarly journals Seed Set Patterns in East African Cooking Bananas are Asymmetric in Bunches and Fruits

2020 ◽  
Author(s):  
Allan Waniale ◽  
Settumba B. Mukasa ◽  
Arthur K. Tugume ◽  
Robooni Tumuhimbise ◽  
Jerome Kubiriba ◽  
...  
Keyword(s):  
Success Rate ◽  
Seed Set ◽  
Gradual Increase ◽  
East African ◽  
Pollination Success ◽  
Random Occurrence ◽  
Hand Pollination ◽  
Wild Banana ◽  
Breeding Efficiency ◽  
Targeted Approach

Abstract Background: Low female fertility in bananas is the biggest hurdle for banana breeding. The aim of this study was to determine seed set patterns in East African cooking bananas EACBs to inform future decisions on a more targeted approach of increasing seed set and subsequently banana breeding efficiency. Matooke (AAA) and Mchare (AA) bananas are genetically distinct but belong to the same genetic complex, they referred to as EACBs. Seed set patterns in ‘Enzirabahima’ (AAA), ‘Mshale’ (AA) and ‘Nshonowa’ (AA) all with residual fertility were examined after hand pollination with a highly male fertile wild banana ‘Calcutta 4’ (AA). Results: Seed set in ‘Enzirabahima’ is predominant in distal hands. Mchare cultivars have a slightly more even distribution of seeds in their hands compared to ‘Enzirabahima.’ There is a gradual increase in seed set from proximal to distal hands with a slight drop in the last hand. This pattern is more definite in ‘Enzirabahima’ and ‘Mshale’ while ‘Nshonowa’ has a somewhat inconsistent pattern. There is also a drop in seed set per 100 fruits per hand from small to larger bunches. However, larger bunches have a higher pollination success compared to smaller bunches. They therefor set more seed on 100 fruits per hand and per bunch basis if bunches without seed are accounted for. Pollination success rate increases from smaller to larger bunches of EACBs. Seed set is biased toward the distal third part of fruits of examined EACBs as well tetraploid Matooke hybrid ‘401K-1’ (AAAA) and improved diploid ‘Zebrina’ GF (AA) that were used for comparison. In comparison, in the highly female fertile ‘Calcutta 4,’ seed set is along the entire length of the fruit.Conclusion: Seed set bias in the distal hands and distal end of fruits suggests a systematic mechanism rather than a random occurrence. It is expected that this information will provide a foundation for increased crossbreeding efficiency in bananas.

scholarly journals Current Scenario of Breeding Approaches in Rice

2021 ◽  
Author(s):  
Suhel Mehandi ◽  
Anita Yadav ◽  
Ramanuj Maurya ◽  
Sudhakar Prasad Mishra ◽  
Syed Mohd. Quatadah ◽  
...  
Keyword(s):  
Management Practices ◽  
Molecular Mapping ◽  
Rice Production ◽  
Yield Potential ◽  
Male Sterile ◽  
Molecular Approaches ◽  
Current Scenario ◽  
Rice Yields ◽  
Breeding Efficiency ◽  
High Yielding Varieties

Rice is the predominant crop in India and is the staple food in eastern and southern Indian populations. One of the oldest grown crops is rice. The initial discovery of cytoplasmic male sterile (CMS) three-line system made it possible to produce hybrids that significantly increase rice yields compared to its inbred counterparts. Further genetic and molecular studies help elucidate the mechanisms involved in CMS male sterility. Additional CMS types were also discovered with similar genetic control from wild sources by interspecific hybridization. In India more than 1200 varieties were released for cultivation suitable different ecosystems and out of them 128 varieties have been contributed from NRRI, Cuttack. A list of these varieties are furnished below with their duration, grain type, yield potential, reaction to major disease and insects grain quality and tolerance to different adverse situations. Recent advances in molecular approaches used in modern rice breeding include molecular marker technology and marker-assisted selection (MAS); molecular mapping of genes and QTLs and production of hybrids and alien introgression lines (AILs). Genomic selection (GS) has been projected as alternative to conventional MAS. GS has huge potential to enhance breeding efficiency by increasing gain per selection per unit time. Due to the adaptation of semi dwarf high yielding varieties, combined with intensive input management practices, the country witnessed an impressive rice production growth in the post-independent period. Rice production was increased four times, productivity three times while the area increase was only one and half times during this period. The projected rice requirement by 2025, in order to keep up with increasing population, is about 130 m.t. The challenge of growing rice production is made more difficult by declining trends in HYV’s yields, decreasing and degrading natural resources such as land and water and a severe labour shortage.

scholarly journals Heterobeltiosis in Banana and Genetic Gains through Crossbreeding

Proceedings ◽  
2020 ◽  
Vol 36 (1) ◽  
pp. 193
Author(s):  
Michael Batte ◽  
Brigitte Uwimana ◽  
Rony Swennen ◽  
Allan Brown ◽  
Helena Persson Hovmalm ◽  
...  
Keyword(s):  
Genetic Gain ◽  
Fruit Yield ◽  
Yield Potential ◽  
Rectangular Lattice ◽  
Hybrid Vigour ◽  
Genetic Gains ◽  
Lattice Design ◽  
Three Generations ◽  
The Mean ◽  
Breeding Efficiency

Heterosis, or hybrid vigour, is the superiority of the hybrid for a certain trait over the mean of its two parents. Heterobeltiosis is a form of heterosis where the hybrid is superior to its best parent. Banana breeding is a tedious, time-consuming process, taking up to two decades to develop a hybrid. Understanding heterosis in banana breeding will contribute to selecting right breeding materials for further crossing, thus increasing banana breeding efficiency. Here we document heterobeltiosis by using the recently bred NARITA ‘Matooke’ hybrids and their ancestors. NARITA hybrids, their parents (4x and 2x), grandparents (3x and 2x), and local 3x ‘Matooke’ cultivar checks were planted in a rectangular lattice design with two replications. Yield and other agronomic data were collected at flowering and harvest. The NARITAs were compared with their 3x ‘Matooke’ grandmothers. Heterobeltiosis on bunch weight was calculated with the data of 3 cycles. All the NARITAs showed heterobeltiosis for bunch weight. NARITA 17 had the highest grandparent heterobeltiosis (ca. 250%). Genetic gains due to crossbreeding were determined for fruit yield considering three generations: matooke cultigen (C0), primary tetraploid hybrids (C1) and secondary tetraploid hybrids (C2). The average genetic gain (from C0 to C2) rates for bunch weight (kg) and yield potential (t ha−1 year−1) were 1.4% and 1.3% per year, respectively.

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