Farmer participation in barley breeding in Syria, Morocco and Tunisia

The paper describes experiments on farmer participation in plant breeding conducted in three countries (Morocco, Syria and Tunisia) on barley, which is the predominant annual rainfed crop in the most marginal areas of these countries. Trials with different types and number of breeding material were planted both on research stations and in farmers' fields. Selection was done by professional breeders and farmers and data were gathered on breeders' and farmers' selection criteria and selection efficiency. The trials reflected the situation of the crop in the three countries, with high yields on station, low yields in some of the most marginal farmers' fields, and poor correlations between research stations and farmers' fields, as well as between farmers' fields. Grain yield was by far the most commonly used selection criterion by the farmers. However, farmers also made a widespread use of selection criteria not normally used by breeders such as grain filling and straw yield, as well as other characteristics of the straw (color) and of the leaves because of the importance of the crop as source of animal feed. A major difference between the selection criteria used by breeders and farmers was disease resistance, almost entirely neglected by the latter. Farmer selection was effective in identifying some of the highest yielding lines in the farmers' own fields and also in those cases where they performed selection on station. The coincidence between entries selected by the breeder and the farmers was high in Morocco but very low in Syria and Tunisia. There were substantial differences between the lines selected by the breeders on station and those selected by farmers in their fields. In Syria, decentralized-participatory selection was significantly more efficient in identifying the highest yielding entries in farmers' fields than any other selection strategy. This work demonstrates that it is possible to organize a plant breeding program so that farmers become major actors in the selection of new cultivars. This revised version was published online in August 2006 with corrections to the Cover Date.     

Specific adaptation and breeding for marginal conditions

Summary Breeding has been very successful in generating cultivars that in favorable environments, and together with large use of fertilizer and chemical control of weeds, pest and diseases, have increased agricultural production several fold. Today the environmental impact of high input agriculture in more favorable environments causes growing concern. By contrast, the impact of breeding in marginal environments has been elusive. The paper discusses evidence showing that the use of breeding principles developed for, and successfully applied, in favorable environments may be the main reason for the lack of breeding progress in marginal environments. Very little breeding work has actually been done in marginal environments, although the theory of correlated responses to selection indicates that selection conducted in good environments or in well-managed experiment stations is not expected to be very efficient when genotype by environment interactions of a cross-over type exist. The assumptions that heritability is higher under good conditions and that there is a carry-over effect of high yield potential are not supported by experimental evidence. If the target environment is below the cross-over point, selection has to be conducted for specific adaptation to that environment. The concept of wide adaptation has more a geographical than an environmental meaning, and it reduces genetic diversity and increases genetic vulnerability. Eventually the issue of genetic heterogeneity versus genetic uniformity is discussed in relation to specific adaptation to marginal environments.     

The cost of participatory barley breeding

Farmer participation in agricultural research is increasingly seen as a powerful methodology to increase the relevance of technologies developed to benefit farmers' communities. In plant breeding, farmer participation is considered as a way to increase the probability of adoption of new varieties. However, the higher expected cost of participatory plant breeding (PPB) is seen as one of the main obstacles to its wider adoption.This paper addresses the issue of the different costs to an Institution of running a PPB program or a non-participatory program and uses the barley-breeding program at the International Center for Agricultural Research in the Dry Areas (ICARDA) as a case study.Observations and data collection were carried out during one full cropping season on the cost of the three main components of the breeding program, i.e. the management of the field trials (land and seedbed preparation, planting, fertilizer application, weed control, harvesting, and seed threshing, cleaning, treating and packaging), the travel to farmers' fields or to the research sites, and the human resources (scientists, technical staff, local workers and farmers) involved in breeding activities.We compared two options for the centralized–non-participatory breeding program, differing in the number of sites (8 and 16) used for the on-farm trials, with 160 options for the decentralized-participatory breeding program, differing in the combination of number of sites (from 4 to 16) and number of trials per site (from 1 to 10).The results show that in both decentralized-participatory and centralized–non-participatory plant breeding the cost of managing the field trials is the highest followed by the cost of human resources and that of travel: the contribution of each component to the total cost varies with the various options and the various combinations of the number of sites and of farmers.The comparison of the aggregated costs indicates that in the case of the ICARDA' barley-breeding program there are no relevant differences between the participatory and the non-participatory plant breeding programs. This is largely associated with the fact that the decentralized-participatory breeding program reaches the same level of development of the breeding material 3 years earlier than the centralized–non-participatory breeding program. Depending on the type of centralized-breeding program and on the combination of number of sites and number of farmers per site in the participatory program, the aggregated costs of the participatory program are lower than those of the centralized-breeding program by between 5 and 28%. At the same level of cost of the centralized program, the model of participatory program used in this study generates more information due to the use of more trials at each site. This improves selection efficiency and provides an analytical tool to optimize the number of sites and of farmers per site.     

Utilization of exotic germplasm in Nordic barley breeding and its consequences for adaptation

Summary Utilization of exotic germplasm is one way to broaden genetic variation in breeding populations. This approach has recently been adopted in Sweden and Finland, where experimental barley populations has been established for research and pre-breeding purposes. The aim of the project is threefold: (1) to increase overall genetic diversity of Nordic barley breeding material; (2) to develop breeding material which possesses a high level of resistance for various barley diseases; and (3) to study effects of exotic germplasm on adaptation and agronomic performance. Both the Finnish and the Swedish barley populations include the same exotic material i.e. unadapted landraces from different parts of Asia and wild barley (Hordeum vulgare ssp. spontaneum) accessions. Locally adapted high-yielding barley lines were included in the populations. The establishment of these populations involved six crossing generations in order to promote recombination and enhance the break-up of linkage blocks. The paper discusses the third aim of the project. Studies on agronomic performance and adaptation showed that (1) agronomically valuable genotypes can be constructed through recombination using exotic germplasm for Nordic conditions, (2) that incorporation of exotic material is most successful when made in a local genetic base and (3) that exotic germplasm has an effect on adaptation.     

Analysis of genetic relationships among 22 European barley varieties based on two PCR markers

Two long primers of 19 (F17) and 20 (F13) nucleotides, respectively,were used in polymerase chain reactions to amplify DNA from differentcultivated barley accessions. These primers can distinguish closely relatedvarieties and, with a unique primer, all the barley accessions analysedshowed a characteristic fingerprint. Sixty per cent and 76% of thefragments generated using F13 and F17, respectively, were polymorphic.The genetic similarity values between accessions were estimated from F13and F17 data. The dendrogram and principal coordinate analysis performedwith F13 data revealed a clear separation of these varieties in accord withtheir pedigree relationships.     

Environment of selection and type of germplasm in barley breeding for low-yielding conditions

Summary Thee groups consisting of 332, 243 and 280 barley breeding lines (entries) of known selection history were evaluated in 10, 9 and 8 environments, respectively, to determine the relationship between grain yield in low yielding (LYE) or high yielding (HYE) environment, and selection history and type of germplasm. One cycle of selection in LYE produced on average five times more entries outyielding the best check in LYE than selection in HYE. A retrospective analysis indicated that the highest yielding lines in LYE were lower yielding (15%–28%) in HYE when compared with the best check, and by 20% and 38% compared with the best entries in HYE. In contrast, the highest yielding lines in HYE were lower yielding (4%–33%) in LYE when compared with the best check, and by 33% and 40% when compared with the best entries in LYE. The highest yielding lines in LYE did not differ consistently from the highest yielding lines in HYE for a number of morphological and developmental traits including days to heading. This suggests there are many paths to high yield in LYE and that analytical breeding based on individual traits may not be appropriate for variable environments. Only 0.07% of the highest yielding entries in LYE was selected for high yield in HYE conditions confirming previous results indicating that selection for high yield in HYE is an inefficient strategy for improving yield in low yielding conditions. This frequency is 28 times lower than the frequency of high yielding entries in LYE selected from landraces or crosses with landraces in low yielding conditions. The results imply that the most cost-effective strategy for barley breeding in low yielding conditions is to select repeatedly in low yielding conditions and to include adapted germplasm (landraces) in the breeding material.     

Yield stability and adaptation of Nordic barleys

Summary Grain yield was studied in a collection of 220 Nordic barley lines at diverse locations in the Nordic countries. Two-row (2r) and six-row (6r) lines differed very significantly in reaction to the growing conditions within and between the two locations, Svalöv (in southern Sweden) and Højbakkegård (in Denmark). This difference was also highly significant at Viikki (in Finland), but not at As (in Norway) or between Viikki and As. Genotype × location (GL) and genotype × year (GY) variance components were used to estimate phenotypic yield stability by Shukla's stability variance (% MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGak0dh9WrFfpC0xh9vqqj-hEeeu0xXdbba9frFj0-OqFf% ea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs0dXdbPYxe9vr0-vr% 0-vqpWqaaeaabaGaaiaacaqabeaadaqaaqaaaOqaaiaabo8adaahaa% WcbeqaaiaabkdaaaGcdaWgaaqcbaCaaiaabMgaaSqabaaaaa!3B73!\[{\text{\sigma }}^{\text{2}} _{\text{i}} \]). Only 7 lines did not contribute significantly to GL- and GY-interactions, and their yield levels were 7–27% lower than that of the highest yielding line (5057 kg/ha). Estimates of GL- and GY-stability parameters were not significantly correlated. Neither responsiveness, measured by the regression coefficient (b _i ), nor phenotypic yield stability, measured by the deviations from regression (Tai's _i ) were correlated with yield. Pedigree studies showed that both b _i and % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGak0dh9WrFfpC0xh9vqqj-hEeeu0xXdbba9frFj0-OqFf% ea0dXdd9vqaq-JfrVkFHe9pgea0dXdar-Jb9hs0dXdbPYxe9vr0-vr% 0-vqpWqaaeaabaGaaiaacaqabeaadaqaaqaaaOqaaiaabo8adaahaa% WcbeqaaiaabkdaaaGcdaWgaaqcbaCaaiaabMgaaSqabaaaaa!3B73!\[{\text{\sigma }}^{\text{2}} _{\text{i}} \] can be changed by recombination and/or induced mutations. Mixing of near isogenic lines with different resistance genes, and selection within a landrace, also resulted in changes in responsiveness. Recently released 2r-cultivars were more unstable than older 2r-cultivars revealed by positive correlation between the year of release and _i . Cultivars originating from southern Scandinavia were higher yielding than cultivars originating from the central or the northern regions of Scandinavia.     

Genetic diversity among elite Bulgarian barley varieties evaluated by RFLP and RAPD markers

Genetic variation among five elite winter barley cultivars (H. vulgare L.) currently grown in Bulgaria was assessed at the molecular level using restriction fragment length polymorphism (RFLP) and randomly amplified polymorphic DNA (RAPD) markers. The present study sampled RFLPs in four well characterized multigene families in barley: the seed storage protein loci; the 18S, 5.8S and 26S ribosomal DNA loci; the loci coding for 5S ribosomal RNA and the loci coding subunit α of ATP-A complex in the mitochondrial genome. RFLPs were detected in three out of five investigated chromosomal loci in the barley cultivars studied. RAPD assay using arbitrary 10-base primers was applied to generate amplified length polymorphic markers in barley. Overall a total of 15 polymorphic phenotypes were found among the studied barley cultivars by using 11 out of 25 tested primers. All RAPDs were considered as dominant genetic markers except for two, where PCR and Southern blot analysis indicated the presence of codominant amplification products. Five RAPD polymorphisms in F₁ and F₂ progenies of the cross between Alpha and Obzor were inherited in Mendelian fashion. The determined values for the genetic variation proved a high genetic similarity among the tested cultivars. Genetic similarity (GS) calculated from RFLP and RAPD data ranged from 0.888 to 0.997 with a mean GS – 0.933. This revised version was published online in July 2006 with corrections to the Cover Date.     

A methodological study on participatory barley breeding II. Response to selection

Farmer participation is increasingly seen as a key to develop technologies which are more relevant to farmers' communities. In plant breeding, farmer participation is seen as key to increase the probability of adoption of new varieties. This paper addresses the issue of selection efficiency in participatory plant breeding by testing the effect of selection environment and of who did the selection in one cropping season (1997) on the performance of the selected lines in the following cropping season (1998). Selection environment had a larger effect on response to selection than who did the selection, confirming the importance of decentralized selection. Selections made by the breeder and the farmers in 1997, differed in 1998 for a number of traits, but seldom for grain yield. When the difference for grain yield was significant, breeder's selection was more effective on station, while farmers' selection was more effective in farmers' fields. The results of this study indicate that it is possible to organize a plant breeding program with the objective of adapting crops to a multitude of both physical and socio-economic environments: such a breeding program will, at the same time, increase productivity and stability, enhance biodiversity and produce environmentally friendly cultivars. This revised version was published online in July 2006 with corrections to the Cover Date.     

Effectiveness of selection for plant characters of barley in simulated segregating rows

Summary Single plants of 12 barley (Hordeum vulgare L. and H. distichum L.) cultivars were randomized to form simulated segregating (mixed) rows. There were 16 mixed rows 15 cm apart, each row containing 24 plants 5 cm apart. In addition, every third row was a control row of one of the cultivars, Bonanza. Each plant was harvested separately.The cultivars differed significantly for all seven characters measured. These seven characters fell into 3 performance groups. Group I characters, seeds/head, 1000 kernel weight, days to ripe and height, showed a higher variance in the mixed rows than in the control rows, had high average heritabilities, and were consistent in performance from one row to another when measured by correlation amongst the cultivars. In Group II, yield/plant and seeds/plant, variance, heritabilities and performance consistency were all low or non-significant. Group III, heads/plant, fell between Groups I and II. These results suggested that single plants with the desired genotype could be successfully selected for characters in Group I only.The frequency with which the most desirable genotype would actually have been chosen with 12.5% selection intensity generally confirmed the above conclusions but indicated that the degree of differences among genotypes was also important in selecting the most desirable genotypes.Contribution No. NRG 77–9 from the Beaverlodge Research Station.     

Tracing sources of dwarfing genes in barley breeding in China

To study the origin ofdwarfing genes used in barley breeding inChina, pedigree data of more than 350 dwarfand semi-dwarf cultivars and entriesdeveloped since 1950 were collected. Theresults showed that 68.4% of them werederivatives of just six accessions:`Chibadamai' (CBDM), `Xiaoshanlixiahuang'(XSLXH), `Cangzhouluodamai' (CZLDM),`Aiganqi' (AGQ), `Zhepi 1' and `Yanfu Aizao3' (YFAZ 3). Therefore, these sixaccessions are considered the main donorsof dwarfing genes to barley cultivars bredin China. `CBDM', `XSLXH' and `CZLDM' arelandraces and were used between 1950 and1980. `AGQ', `Zhepi 1' and `YFAZ 3' arereleased cultivars used since 1980. `CBDM',`XSLXH', `CZLDM' and `AGQ' carry the samedwarfing gene uzu on chromosome arm3HL. `Zhepi 1' and `YFAZ 3' likely aremutations at the sdw 1 locus.     

Geographical differentiation and diallel analysis of seed dormancy in barley

Seed dormancy is one of the most important parameters affecting the malting process and pre-harvest sprouting in barley (Hordeum vulgare L.). Variation of seed dormancy in 4365 cultivated and 177 wild barley (ssp. spontaneum) accessions derived from different regions of the world was investigated in Okayama University, Kurashiki, Japan. Seed dormancy of each accession was estimated from their germination percentages at 0, 5, 10 and 15 weeks post-harvest after-ripening periods. All of the wild barley accessions showed less than 10% germination at 0 week after-ripening period. Level of seed dormancy in 4365 cultivated barley accessions showed a clear geographical differentiation. Seventy seven percent of Ethiopian accessions showed high germination percentages, while 86% of Japanese, Turkish and North African accessions showed low germination percentages at 0 week after-ripening period. A half diallel cross using eleven barley accessions with different level of dormancy revealed that seed dormancy was predominately controlled by additive gene effects. These results suggest that large genetic diversity for seed dormancy in barley is explained as different levels of additive accumulation of genetic factors. Barley varieties showing appropriate dormancy could be developed by crossing among barley germplasm accessions used in the present study.     

Non-parametric measures of phenotypic stability in chickpea genotypes (<Emphasis Type="Italic">Cicer arietinum</Emphasis> L.)

Multi-environment trials (MET) play an important role in selecting the best cultivars and/or agronomic practices to be used in future years at different locations by assessing a cultivar's stability across environments before its commercial release. Objective of this study is to identify chickpea (Cicer arietinum L.) genotypes that have high yield and stable performance across different locations. The genotypes were developed by various breeders at different research institutes/stations of Iran and the International Center for Agricultural Research in Dray Areas (ICARDA), Syria. Several statistical methods were used to evaluate phenotypic stability of these test chickpea genotypes. The 17 genotypes were tested at six different research stations for two years in Iran. Three non-parametric statistical test of significance for genotype × environment (GE) interaction and ten nonparametric measures of stability analyses were used to identify stable genotypes across the 16 environments. The non-parametric measures (Kubinger, Hildebrand and Kroon/Van der) for G × E interaction were highly significant (P < 0.01), suggesting differential responses of the genotypes to the test environments. Based on high values of nonparametric superiority measure (Fox et al. 1990) and low values of Kang's (1988) rank-sum stability parameters, Flip 94-123C was identified as the most stable genotype. These non parametric parameters were observed to be associated with high mean yield. However, the other nonparametric methods were not positively correlated with mean yield and were therefore not used in classifying the genotypes. Simple correlation coefficients using Spearman’s rank correlation, calculated using ranks was used to measure the relationship between the stability parameters. To understand the nature of relationships among the nonparametric methods, a hierarchical cluster analysis based on non weighted values of genotypes, was performed. The 10 stability parameters fell into three groups.     

A recurrent selection programme for grain yield in winter barley

Summary The effect of a recurrent selection procedure was evaluated in a winter barley (Hordeum vulgare L.) population. Cycle zero (C₀) was initiated by crossing six high yielding winter barley cultivars with the short straw cv Onice. The F₁'s were crossed according to a diallel scheme without reciprocals. A total of 750 S₀ plants were derived and evaluated; 329 S₀ plants were selected and their progenies (S₁ lines) tested. Fifteen S₁ lines were chosen and used as parents of cycle 1 (C₁), by producing 105 F₁ hybrids which simulated a random mating offspring. One hundred and three randomly chosen S₁ lines belonging to C₀, and 103 S₁ lines belonging to C₁, were evaluated at two locations.For grain yield a significant difference between cycles was observed. From C₀ to C₁ the grain yield increased with 307 g/m². This increase was due to a higher number of seeds per m². For plant height, heading date and 100-kernel weight no differences between cycles were observed.The positive results obtained in this study indicate the potential usefulness of recurrent selection for developing parents or lines superior for grain yield, with little change in other important agronomic traits.     

Simultaneous selection of segregating two-row winter barley material in England and Italy

Summary Independent but simultaneous selection by two breeding teams of the same segregating two-row winter barley material at Cambridge, England and Fiorenzuola, Italy was carried out over the years 1978–1982 with the objective of comparing the individual selection of the two breeding teams and assessing the adaptation of the surviving selections. Visual selection in the generations F₃ to F₅ did not result in any clear cut compartmentalisation of the material and both teams were as likely to select from families previously selected only by the other team as from families they had themselves previously selected. Lines with specific adaptation to each site as well as lines well adapted to both sites were identified from yield trials carried out in F₅ and F₆. The former showed only a very small yield advantage over lines with general adaptation to both sites.     

Relationship between barley grain yield measured in low- and high-yielding environments

Summary The paper addresses the general question of identifying the optimum environment for selection in plant breeding programs for low input agricultural systems. After defining low-yielding and high-yielding environments based on the average grain yield of large numbers of barley genotypes in different cropping seasons, we examined: 1) the phenotypic relationships between the highest yielding genotypes in low- and high-yielding environments, and 2) the genetic correlation coefficients between grain yield in low- and high-yielding environments. The results indicate that the alleles controlling high grain yield in low-yielding conditions are at least partially different from those controlling high grain yield in high-yielding conditions. Therefore, selection in high-yielding environments is expected to produce a negative response or no response in low-yielding environments. This may explain why crop varieties bred under high-yielding conditions failed to have an impact in low-yielding agricultural systems. The results may be extrapolated to systems where environmental concern suggests a reduction of inputs by raising the question of whether crop breeding programs based on selection under high inputs are likely to generate the right type of germplasm for an environmentally friendly agriculture.     

A rapid method for screening barley for aluminium tolerance

Summary A method for rapid screening of large numbers of barley genotypes for aluminium tolerance is described, and the results of a small scale screening of composite cross CC XXX-C given.     

Salt stress tolerance in heterogeneous populations of barley

Summary Four highly heterogeneous populations of barley were assayed for salt stress tolerance at the time of seed germination. Three of these, Davis, Dryland and Irrigated, were derived originally from a population called Composite Cross XXI and propagated until F₁₇ under contrasting conditions. The fourth, Composite Cross XXX-C, was of relatively recent (F₅) origin. This population showed the highest germinability in nutrient solution salinated with sodium chloride. Davis was poorer in salt tolerance than CC XXX-C but better than Dryland and Irrigated. Dryland and Irrigated, propagated for 14 successive genrations under contrasting levels of soil moisture, showed no significant difference in salt stress tolerance. In several hundred random samples of lines developed from these two populations, ear row number, lemma awn texture, seed weight and yield showed non-random associations with salt tolerance. These associations might be gainfully utilized in barley breeding for salt stress tolerance.     

Race differentiation and search for sources of resistance to Rhynchosporium secalis in barley in Italy

Summary Barley in Italy has recently been seriously affected by Rhynchosporium secalis. The pathogenic variation of the fungus was studied and 17 races were differentiated on 13 barley cultivars carrying most of the currently known genes for resistance. RC 1, the most virulent and most frequent race, was virulent on 10 out of the 13 differentials and the remaining races proved to be less virulent variants of RC 1. Atlas (C.I. 4118), Atlas 46 (C.I. 7323) and Osiris (C.I. 1622) were the only three differentials resistant to all the analyzed single-spore isolates.Differential cultivars previously assumed to have identical resistance factors did not react in the same way to all the Italian races, thereby revealing either undisclosed differences in the genes described or the presence of additional unidentified ones.Our findings were compared with previous data about virulence of scald populations from different countries, on the basis of tests with common differentials: fundamental differences were found between the Italian population and those of other countries with regard to virulence patterns.The susceptible reactions to race RC 1 of most barley cultivars grown in Italy indicate the urgent need for resistance genes to be incorporated in the cultivated material. Seventy-one barley accessions, known as sources of resistance in different parts of the world, were screened for their behaviour to races RC 1 and RC 13. Twenty-two appeared resistant to both of them.     

Inheritance and geographical distribution of phenol reaction-less varieties of barley

Summary The reaction of spikes and grains of barley to phenol was investigated using 8,849 cultivated and 349 wild accessions collected from the world. The pericarp and hull of the grain were stained dark brown by a 1% phenol solution and the reaction of awn was sharpest. Phenol reaction was controlled by a dominant gene, named Phr (phenol reaction) which was located on chromosome 2. All the wild strains of various Hordeum species showed a positive reaction to phenol indicating it was the prototype of the trait. Only 51 accessions of cultivated barley showed negative reaction to phenol. They were distributed along the so-called Silk-road and the type of variety was limited suggesting that it was a rather new mutation which occurred in the Middle East. Synteny of the chromosome region involving the phenol reaction gene in some gramineous plants was discussed.