Landrace Cultivars Research Articles

High Quantitative Trait Variability in Faba Bean Mutagenized Population for High-yielding Breeding Program in Saudi Arabia

Background: The narrow genetic base and environmental stresses are behind the low rate of faba bean yield in the past two decades. Drought stress is one of the most destructive abiotic stresses. Using induced mutagenesis on locally adapted landrace cultivar is proposed to cope with this problem. Methods: This study was conducted on faba bean landrace cultivar of Saudi Arabia, namely Hassawi 2, treated by 25 and 50 Gray gamma radiation. The genetic diversity assessment of M2 mutant populations was based on seven quantitative traits and nine Amplified Fragment Length Polymorphism (AFLP) primer combinations. Result: A total of 3419 M2 seeds were planted, of which 2782 (81.4%) seeds germinated and 2658 plants survived. A 5 to a 10-fold range of quantitative traits studied among mutant plants compared to control plants showed high variability. The number of pods per plant and seeds per plant was a valid selection criterion for a high-yielding faba bean breeding program. Nine AFLP primer combinations generated 1079 polymorphic alleles from 88 samples that comprised mutant and control plants. Shannon index (I) and expected heterozygosity (He) were 0.337 and 0.206, respectively. The AFLP results validated high variability in M2 populations. These findings will assist faba bean breeders in developing high-yielding cultivars with drought stress tolerance.

DWARF and SMALL SEED1, a Novel Allele of OsDWARF, Controls Rice Plant Architecture, Seed Size, and Chlorophyll Biosynthesis

Plant architecture is a vital agronomic trait to control yield in rice (Oryza sativa L.). A dwarf and small seed 1 (dss1) mutant were obtained from the ethyl methanesulfonate (EMS) mutagenized progeny of a Guizhou glutinous landrace cultivar, Lipingzabianhe. The dss1 mutant displayed phenotypes similar to those of brassinosteroid (BR) deficient mutants, such as dwarfing, dark green and rugose erect leaves, small seeds, and loner neck internode panicles with primary branching. In our previous study, the underlying DSS1 gene was isolated, a novel allele of OsDWARF (OsBR6ox) that encodes a cytochrome P450 protein involved in the BR biosynthetic pathway by MutMap technology. In this work, we confirmed that a Thr335Ile amino acid substitution residing in DSS1/OsDWARF was responsible for the dwarf, panicle architecture, and small seed phenotypes in the dss1 mutants by genetic transformation experiments. The overexpression of OsDWARF in the dss1 mutant background could not only recover dss1 to the normal plant height and panicle architecture but also rescued normal leaf angles, seed size, and leaf color. Thus, the specific mutation in DSS1/OsDWARF influenced plant architecture, seed size, and chlorophyll biosynthesis.

Floral Biology and Pollination Efficiency in Yam (Dioscorea spp.)

Yam (Dioscorea spp.) is a monocotyledonous herbaceous vine cultivated for its starchy underground or aerial tubers in the tropics and subtropics. It is an allogamous and polyploid species that reproduces by both sexual and asexual mechanisms. However, many of the landrace cultivars, including most of the popular varieties, reproduce exclusively by vegetative propagation (planting the tubers). These varieties are either sterile or produce sparse and irregular flowering with high flower abortion rate, low fruit and seed set. Production of crossbreed seeds for genetic improvement and for maintaining genetic diversity in yams is, therefore, mainly achieved through natural or managed pollination. Flowering in yam is mostly dioecious and, in some instances, monoecious. Flowering asynchrony, sticky nature of the pollen grains, and cross incompatibility are among the challenges in making genetic progress in yam breeding. There are many limitations in basic and applied knowledge of yam flower biology and pollination. This paper, therefore, reviews the flowering biology, pollination, and methods of improving pollination efficiency in yam breeding programs.

Nutritional characterization and productivity evaluation of landrace maize cultivars

O objetivo deste trabalho foi identificar cultivares crioulas de milho com altos teores nutricionais e produtividade. Determinaram-se os parâmetros biométricos, os teores de matéria seca, cinzas, proteínas e lipídios e o perfil de ácidos graxos e minerais dos grãos de 15 cultivares crioulas de milho e duas testemunhas melhoradas (‘BRS 1002’ e ‘BRS Missões’). As cultivares de milho foram cultivadas na safra 2010/2011, em Ibarama, RS, Brasil. As testemunhas melhoradas de milho apresentaram desempenho similiar ao da maioria das cultivares crioulas quanto aos parâmetros biométricos; no entanto, a ‘BRS 1002’ mostrou a maior produtividade. As cultivares crioulas ‘Cateto Amarelo’, ‘Ferro’, ‘Mato Grosso’ e ‘Cinquentinha’ mostraram-se mais nutritivas do que as demais cultivares analisadas. A mensuração do valor genético foi eficiente para as características analisadas nos grãos das cultivares. As cultivares estudadas, em especial as crioulas que apresentam maiores quantidades de nutrientes, podem ser empregadas na indústria alimentícia para a fortificação de alimentos e a produção de óleos.

Sprouting bioprocess as a sustainable tool for enhancing durum wheat (Triticum durum) nutrients and bioactive compounds

Background: Consumers are more aware of the role of healthy diet in preventing food-related diseases (Cancer, cardiovascular diseases, diabetes, etc.). Consequently, they are looking for products with beneficial nutritional attributes that encourage the food industry to develop functional foods. Aims: In this study, we aimed at using a natural bioprocess to improve durum wheat “Triticum durum” nutritional properties for its further use as a functional ingredient. Materials and Methods: Six durum wheat cultivars were tested: four high yielding and two landrace ones. Seeds were germinated for 48 hours at 22°C. Nutritional properties were evaluated through proximate composition and bioactive compounds (carotenoids, total phenol, vitamin C and tocopherols) levels. Results: Biochemical characterization of sprouted seeds showed significant modifications with a decrease in ash, starch contents and an increase in reducing sugars, and in proteins. Improvements in bioactive compounds were also observed in sprouted seeds. Vitamin C, tocopherols, total phenols, carotenoid pigments as well as antioxidant activity significantly increased after sprouting. Interestingly, durum wheat landrace cultivars showed the best performances. Conclusions: Results provided by our study proved that sprouting is an interesting natural tool to use in the food industry for the development of cereal products with added nutritional value. Keywords: Durum wheat, bioactive compounds, nutritional properties, sprouting, vitamins.

Root traits of dryland winter wheat (Triticum aestivum L.) from the 1940s to the 2010s in Shaanxi Province, China

Eight cultivars of winter wheat (Triticum aestivum L.) adapted to dryland conditions that have been historically planted in Shaanxi Province, China, were grown in plots with irrigation and drought treatments during the growing seasons of 2010–2012 to characterize the changes in root system traits and water use efficiency during the replacement of cultivars. The results showed that the overall root size of dryland wheat cultivars in Shaanxi Province changed with the planting decade. Modern cultivars developed after the 2000s had larger root surface areas than older cultivars under the drought treatment, especially at soil depths of 0–40 cm. However, the total water consumption throughout the stages showed no obvious changes among cultivars. The yield significantly increased with the planting decade, and the water use efficiency showed an average increase of 47.07% from the earliest to the most recent studied cultivar. Water stress promoted larger root sizes than those found in the irrigation treatment, especially at maturity. A trend toward a lower stress susceptibility index was observed over the decades, indicating that the sizes of modern cultivar roots increased less in the drought treatment than in the irrigation treatment. Both the roots and yields of the landrace cultivar from the 1940s showed low sensitivity to drought and better adjustment between the different water conditions. The study revealed that (1) modern wheat cultivars in Shaanxi Province possess higher water use efficiencies and decreased drought resilience and (2) the selection of ideal root traits should consider stable yields under different water conditions.

English

Leaf rust caused by the pathogen Puccinia triticina is one of the important diseases of wheat in Ethiopia; and yield loss due to this disease has reached up to 75%. A study was carried out to detect physiologic races of the pathogen from some parts of Bale, Gondar and Shewa and to identify seedling resistance of Ethiopian durum cultivars. Twenty-four mono pustule isolates were made, and out of those, only three P. triticina races namely; BBBB, BBBN and BBBQ were identified. Race BBBN was detected for the first time in Ethiopia and was less virulent to commercial durum wheat cultivars than BBBQ and BBBB, while phenotype BBBB was relatively highly virulent to Ethiopian durum wheat and it infect 42.5% of the tested cultivars and is not virulent to Thatcher and Thatcher isoline leaf rust differential cultivars. Thirty six commercial durum wheat cultivars and three land race cultivars were evaluated against those three leaf rust pathogen races at seedling stage in the green house at Debre-Zeit Agricultural Research Center. Varieties Utuba, Lelisa, Worer, Bekelcha, Tate, Filakit, Foka, Alem tena, Hitosa, Kilinto, Denbi, Ude, LD-357, Boohai, Mukuye, Robe, Mangudo and Assasa exhibited resistance reaction (; to 2) to all the three leaf rust races, while the rest showed susceptible at least to one of the race. All the three land race cultivars (Mcd4-12, Mcd4-32 and Mcd7-42) were susceptible to all pathogen races. Key words: Durum wheat, leaf rust, Puccinia triticina, race, seedling resistance.

Physiological diversity in Brazilian common bean (Phaseolus vulgaris L.) landraces based on selection index

Common bean landraces represent heterogeneous, local adaptations of domesticated species, and thereby provide genetic resources that meet current and new challenges for farming. These local ecotypes can show variable phenology and low-to-moderate edible yield, however, they are highly nutritious. Therefore, strategies to stimulate the conservation of this genetic diversity are important. The maintenance of seed germination potential is also an important feature in the characterization of genetic diversity to conserve biodiversity. The main objective of this study was to discriminate common bean landrace cultivars available at Santa Catarina State University (UDESC) germplasm bank according to their seed physiological diversity and agronomic parameters (germination rate, viability, seed vigor, and seedling growth) and based on Mulamba and Mock selection index. There is a large physiological diversity in common bean landrace cultivars. BAF 112 and BAF 81, BAF 84, BAF 42, BAF 60, and BAF 75, were identified as more promising for the storage of the seeds under conventional conditions, being able to maintain the viability and vigor during storage. Mulamba and Mock selection index were capable of selecting superior cultivars with high physiological quality.

‘NABIO808’ (Syn. ‘NAROBAN5’): A tasty cooking banana cultivar with resistance to pests and diseases

Abstract ‘NABIO808’ is a newly released, conventionally-bred triploid cooking banana cultivar in Uganda. It produces an average bunch yield of 54.5 t ha-1 yr-1 and is resistant to weevils, nematodes, and black Sigatoka. Additionally, its food is yellow, soft, and tasty, like that of most preferred landrace cultivars, making it more acceptable to end-users.

Mining and genomic characterization of resistance to tan spot, Stagonospora nodorum blotch (SNB), and Fusarium head blight in Watkins core collection of wheat landraces

BackgroundIn the late 1920s, A. E. Watkins collected about 7000 landrace cultivars (LCs) of bread wheat (Triticum aestivum L.) from 32 different countries around the world. Among which 826 LCs remain viable and could be a valuable source of superior/favorable alleles to enhance disease resistance in wheat. In the present study, a core set of 121 LCs, which captures the majority of the genetic diversity of Watkins collection, was evaluated for identifying novel sources of resistance against tan spot, Stagonospora nodorum blotch (SNB), and Fusarium Head Blight (FHB).ResultsA diverse response was observed in 121 LCs for all three diseases. The majority of LCs were moderately susceptible to susceptible to tan spot Ptr race 1 (84%) and FHB (96%) whereas a large number of LCs were resistant or moderately resistant against tan spot Ptr race 5 (95%) and SNB (54%). Thirteen LCs were identified in this study could be a valuable source for multiple resistance to tan spot Ptr races 1 and 5, and SNB, and another five LCs could be a potential source for FHB resistance. GWAS analysis was carried out using disease phenotyping score and 8807 SNPs data of 118 LCs, which identified 30 significant marker-trait associations (MTAs) with -log10 (p-value) > 3.0. Ten, five, and five genomic regions were found to be associated with resistance to tan spot Ptr race 1, race 5, and SNB, respectively in this study. In addition to Tsn1, several novel genomic regions Q.Ts1.sdsu-4BS and Q.Ts1.sdsu-5BS (tan spot Ptr race 1) and Q.Ts5.sdsu-1BL, Q.Ts5.sdsu-2DL, Q.Ts5.sdsu-3AL, and Q.Ts5.sdsu-6BL (tan spot Ptr race 5) were also identified. Our results indicate that these putative genomic regions contain several genes that play an important role in plant defense mechanisms.ConclusionOur results suggest the existence of valuable resistant alleles against leaf spot diseases in Watkins LCs. The single-nucleotide polymorphism (SNP) markers linked to the quantitative trait loci (QTLs) for tan spot and SNB resistance along with LCs harboring multiple disease resistance could be useful for future wheat breeding.

Characterization of cassava (<em>Manihot esculenta</em> Crantz) cultivars in Sri Lanka using morphological, molecular and organoleptic parameters

Cassava (Manihot esculenta Crantz), an important dietary staple in many countries, supplies food for one billion people in the world. Due to dietary importance, currently cassava cultivation is promoted in Sri Lanka. Even though there are different cassava cultivars grown, no studies have been conducted on cultivar discrimination and preference on their tubers for consumption. Therefore, the present study was conducted to study the morphological and genetic diversity, and assess the consumer preference of cassava cultivars grown in Sri Lanka. Morphological traits of leaves, stems and tubers, chlorophyll content, ascorbic acid content of leaves, dry matter content of leaves and tubers were recorded. The genetic diversity was assessed by sequencing and analyzing the ITS, a DNA barcoding locus. The leaf morphology of wild-accession and Landrace cultivars were considerably different from the rest. The stem morphology was highly different, mainly in the internodal length. A significantly high number of tubers were observed in the cultivar Suranimala. The significant associations were observed from color, aroma, texture, bitterness, hardness and overall taste vs. cassava cultivars. The nine cultivars were separated through ITS polymorphism. In phylogenetic analysis, wild-accession was the most genetically distant type having nine unique SNPs and one INDEL. Other cultivars were mainly divided into two clusters. Thus, it is possible to employ ITS barcoding marker to discriminate the cultivars of M. esculenta.

Maize: Key agricultural crop in food security and sovereignty in a future with water scarcity

ABSTRACT The objective in this review was to discuss the importance of maize currently and the crucial role it may play in the future for food production in scenarios of water shortage, as well as the importance of conserving its landrace cultivars, which have a considerable portion of the reserve of genetic variability. Maize plants, when exposed to water deficit, may develop physiological, morphological, biochemical and anatomical adaptation mechanisms. With the aid of genetic improvement, characteristics that impart tolerance are fixed in plants through conventional methods. In this context, ‘Tuxpeño Sequia’ cultivars were developed in Mexico, while in Africa, one of the most important strategies was the development of ‘DT’ (Drought-tolerant) cultivars. In the United States, one of the most important processes was the development of PionerAquamax® hybrids, while in Brazil, it was the development of cultivars with the ‘Maya Latente’ gene. Through genetic transformation, the hybrid ‘MON 87460’ was developed. However, it should be mentioned that, for a cultivar to be well accepted by producers, besides having one or more adaptation characteristics, it must have a high grain yield. Biotechnological tools such as the use of molecular markers, genetic transformation, and modeling through bioinformatics, associated with conventional selection, will be fundamental to guarantee the advancement of water deficit tolerance in maize.

Evaluation of Ethiopian Durum Wheat Varieties and Landrace Cultivars for the Adult Plant Resistance of Wheat Leaf Rust (Puccinia triticina)

Wheat Leaf rust caused by the pathogen Puccinia triticina is a serious threat of wheat production in Ethiopia, yield loss due tothis disease reached up to 70%. A study was carried out to identify leaf rust adult plant resistance in commercial durum wheatcultivars and landraces. 35 durum wheat Varieties and 200 durum wheat landraces with three susceptible checks arranged inAugment design and evaluated against leaf rust at Debere Zeit Agricultural Research Center, Ethiopia during the 2017/18 mainseason. Terminal Rust Severity (TRS), Coefficient of Infection (CI), Area under Disease Progress Curve (AUDPC) and Disease Progress Rate (DPR) were used to measure leaf rust adult plant resistance in the test materials. Analysis of all disease parameters was carried out using SPAD software. There were highly significant differences (Pl0.01) for all disease parameters among the test cultivars. Above half of evaluated Varieties and landraces (57.9 %) showed better Adult plant resistance under high disease pressure. From the total of 235 tested Varieties and landraces, 136 had slow rusting resistance of which 14 were released varieties and the rest 122 were landraces. Four commercial Varieties (Selam, Mossobo, Bekelcha, and Utuba) and a landrace cultivar (Mcd4-32) had high levels of field resistance with very low AUDPC, ACI, and TRS with MR infection type; hence, they may carry major resistance gene (s). However, the rest 99 Varieties and landraces exhibited high to moderate level of slow rusting resistance with MS responses and may have adult plant resistance controlled by minor resistance genes. The slow rusting cultivars identified from the current study can be used for further manipulation in wheat improvement programs.

Evaluation of Lines from a Farmer Participatory Organic Wheat Breeding Program

Involving farmers directly in early‐generation selection may contribute to the development of well‐adapted organic wheat (Triticum aestivum L.) germplasm. This project involved a partnership between a professional breeder and farmers. Progeny from 19 spring wheat crosses were distributed to eight organic farmers (three populations per farmer) in southern Manitoba, Canada. Each farmer selected for three consecutive years, resulting in 23 unique advanced lines. The farmer‐selected lines were compared with eight registered cultivars and one landrace cultivar in replicated field experiments at a total of three site years in 2014 and 2015. Although there was significant variation in agronomic performance of different farmer‐selected lines, the farmer selections were generally taller, later maturing, more susceptible to lodging; farmer selections were higher yielding than the check cultivars at one site‐year. When selecting from the same population, farmers produced distinctively different lines; differences were observed in disease response, days to maturity, height, lodging, and yield. The highest yielding wheats included farmer‐selected lines, a heritage cultivar, and two modern checks, one bred for organic conditions and one with a unique insect resistance trait. This preliminary study shows the potential of farmers working together with a professional breeder to produce wheat germplasm for organic production. Results also confirm the value of certain conventional cultivars to organic production.

Molecular characterization of a novel vernalization allele Vrn-B1d and its effect on heading time in Chinese wheat (Triticum aestivum L.) landrace Hongchunmai

Flowering time of wheat cultivars contributes greatly to the adaptability to environmental conditions and it is largely controlled by vernalization genes. In this study, 262 Chinese mini-core wheat cultivars were used to identify the allelic variation at VRN-B1 locus. A novel dominant allele Vrn-B1d was found in Chinese spring wheat landrace cultivar Hongchunmai. This allele contained several genetic divergence within the first intron comparing to the recessive allele vrn-B1, including one large 6850-bp deletion (670–7519 bp), one small 187-bp deletion (7851–8037 bp), one unique SNP (T to C, 7845 bp), and one 4-bp mutation (TTTT to ACAA, 7847–7850 bp). Meanwhile, it was also different from the three known dominant alleles at VRN-B1 locus. Two pairs of primers were designed to identify the novel allele Vrn-B1d and other four known alleles of VRN-B1. A multiplex PCR was established to discriminate all five alleles simultaneously. The greenhouse experiment with high temperature (non-vernalizing condition) and long light showed that F2 plants containing Vrn-B1d allele headed significantly earlier than those with recessive vrn-B1 allele, suggesting that Vrn-B1d is a dominant allele conferring the spring growth habit. This study provides a useful germplasm and molecular markers for wheat breeding.

Adult plant leaf rust resistance derived from the wheat landrace cultivar Americano 44d is conditioned by interaction of three QTL

Americano 44 is a landrace derived wheat cultivar from Uruguay that has had long lasting resistance to the leaf rust pathogen Puccinia triticina. A population of 92 recombinant inbred lines derived from the cross ‘Thatcher*3/Americano 44d’ was evaluated for segregation of adult plant leaf rust resistance in four field plot tests and two greenhouse tests. A genetic map was constructed with 381 Diversity Array Technology markers, five simple sequence repeat markers, and seven kompetitive allele specific PCR markers. Significant effects for reduction of leaf rust severity were found for quantitative trait loci (QTL) on chromosomes 3AS, 3DS and 6DS. Individually the 3AS and 3DS regions did not decrease leaf rust severity in any of the tests compared to the susceptible parent, yet strongly interacted when present in the same genotype to decrease leaf rust severity equal to the resistant parent. Genotypes with only the 6DS region had significantly lower leaf rust severity compared to the susceptible parent in three of the field plot tests. The 6DS QTL also interacted with the 3DS QTL to decrease leaf rust severity. Major QTLs on chromosome 3AS and 3DS are both located in the distal region and may be encoded by homoeoalleles.

Simple Sequence Repeat Markers Reveal Hungarian Plum (Prunus domestica L.) Germplasm as a Valuable Gene Resource

The hexaploid European plum (Prunus domestica L.) is an economically important fruit species with limited information on its genetic structure. Our objective was to fingerprint 55 cultivars using seven simple sequence repeat (SSR) markers to estimate the polymorphism level and determine allelic variation and genetic relationships among local and international cultivars. The primer pairs amplified a total of 135 alleles ranging from six to 27 alleles per locus, displaying high polymorphism. All genotypes were clearly distinguished with the seven SSRs used in this study. In a neighbor-joining cluster analysis, cultivars belonging to the same species did not group together. Foreign modern cultivars clustered together, and Hungarian landraces positioned distantly from those. STRUCTURE analysis indicated three genetically distinct groups of the studied genotypes. Each cluster of Hungarian landrace cultivars received strong bootstrap support (89% to 100%). Most genotypes kept under identical name showed different DNA fingerprints. A principal component analysis (PCA) confirmed the information provided by the dendrogram and clarified the origin of ʻFehérszilva’. Our results confirmed the potential of the application of SSR markers in plum breeding.

AFLP Molecular Identification and Genetic Relationship of Chinese and Japanese Pear Cultivars Grown in Middle European Conditions

In this study, 30 genotypes of genus Pyrus (five European cultivars, 16 Asian cultivars, three rootstocks, four interspecific hybrids, one landrace cultivar from Czech Republic (‘Krvavka’), Pyrus betulaefolia Bunge. and one intergeneric hybrid (Cydomalus)) were tested using AFLP markers. Twelve primer combinations generated a number of 1251 fragments of which 1064 were polymorphic with an average polymorphism of 85.3%. The dendrogram, created by using the UPGMA method, revealed a distinct genetic relationship between European and Asian pear groups. The intergeneric hybrid Cydomalus was separated in the cluster tree from both groups. The level of similarity coefficient between European and Asian pears was 0.75. Despite the fact that Pyrus betulaefolia Bunge was clustered in the European pear group, the average similarity coefficient between the European pear group and Pyrus betulaefolia Bunge (0.7704) was comparable to the similarity coefficient between the Asian pear group and Pyrus betulaefolia Bunge (0.768). Thus, the botanic species Pyrus betulaefolia Bunge can likely be considered as an intermediate genotype between European and Asian pears. The cultivar ‘Talgarskaja Krasavica’ (chance seedling of ‘Forest Beauty’), which pomologically belongs to the European pear group was clustered together with the interspecific hybrid ‘Wu Jiu Xinag’ (‘Ya Li’ × ‘Bartlett’) which on the other hand belongs to the Asian pear group. Thus, due to its position in the dendrogram the cultivar ‘Talgarskaja Krasavica’ could be considered as an interspecific hybrid.

Genetic analysis of the Lf1 gene that controls leaflet number in soybean.

A high-resolution genetic map that was constructed for the Lf1 -residing region will provide valuable information for map-based cloning and genetic improvement efforts in soybean. Changes in leaf architecture as photosynthesis factories remain a major challenge for the improvement of crop productivity. Unlike most soybeans, which have compound leaves comprising three leaflets, the soybean Lf1 mutant has a high frequency of compound leaves with five leaflets in a partially dominant manner. Here, we generated a fine genetic map to determine the genetic basis of this multifoliolate leaf trait. A five-leaflet variant Dusam was found in a recently collected landrace cultivar. Phenotypic data were collected from the F2 population of a cross between the Dusam and three-leaflet cultivar V94-5152. The mapping results generated using public markers indicated that the five-leaflet determining gene in Dusam is an allele of the previously studied Lf1 gene on chromosome 8. A high-resolution map delimited the genomic region controlling the leaflet number trait to a sequence length of 49kb. AP2 domain-containing Glyma.08g281900 annotated in this 49kb region appeared to be a strong candidate for the Lf1-encoding gene, as members of the AP2-type transcription factor family regulate lateral organ development. Dusam additionally exhibits visually distinct phenotypes for shattering and seed-coat cracking traits. However, the two traits were clearly unlinked to the Lf1 gene in our mapping population. Interestingly, the mapping results suggest that the Lf1 gene most likely exerts a pleiotropic effect on the number of seeds per pod. Thus, our results provide a strong foundation towards the cloning of this compound leaf development gene and marker-assisted selection of the seeds per pod trait.

Effect of several rhizobacteria strains on barley resistance againstPyrenophora gramineaunder field conditions

SummaryThe effect ofPseudomonas putidaBTP1,Bacillus subtilisBs2500, Bs2504, and Bs2508 strains on the incidence (I) and severity (S) of barley leaf stripe disease caused byPyrenophora gramineawas evaluated under field conditions. Three barley cultivars varying in resistance level were used. The resistance achieved in our study was long-lasting.P. putidaBTP1 and Bs2508 were in general the most effective strains in reducing significantly both I and S of barley leaf stripe disease vis-a-vis three cultivars in two growing seasons 2013/2014. The disease was reduced up to 66% in Arabi Abiad treated withP. putidaBTP1. The susceptible landrace cultivar Arabi Abiad exhibited a significant induction of resistance by Bs2508 and BTP1. However, the resistant cultivar Banteng did not exhibit significant further increase in resistance by these bacterial strains. The grain yield of bacterized plants artificially inoculated withP. gramineawas not affected, except that of the cultivar Arabi Abiad treated with Bs2508 and Bs2504. Triggering of resistance by treating seeds with the bacterial strains would be of great value in agriculture, especially in case of barley infection byP. gramineaat an early stage of plant development.