Orchardgrass Genotypes Research Articles

Transcriptome Profiling Provides Insights into the Early Development of Tiller Buds in High- and Low-Tillering Orchardgrass Genotypes.

Orchardgrass (Dactylis glomerata L.) is among the most economically important perennial cool-season grasses, and is considered an excellent hay, pasture, and silage crop in temperate regions worldwide. Tillering is a vital feature that dominates orchardgrass regeneration and biomass yield. However, transcriptional dynamics underlying early-stage bud development in high- and low-tillering orchardgrass genotypes are unclear. Thus, this study assessed the photosynthetic parameters, the partially essential intermediate biomolecular substances, and the transcriptome to elaborate the early-stage profiles of tiller development. Photosynthetic efficiency and morphological development significantly differed between high- (AKZ-NRGR667) and low-tillering genotypes (D20170203) at the early stage after tiller formation. The 206.41 Gb of high-quality reads revealed stage-specific differentially expressed genes (DEGs), demonstrating that signal transduction and energy-related metabolism pathways, especially photosynthetic-related processes, influence tiller induction and development. Moreover, weighted correlation network analysis (WGCNA) and functional enrichment identified distinctively co-expressed gene clusters and four main regulatory pathways, including chlorophyll, lutein, nitrogen, and gibberellic acid (GA) metabolism pathways. Therefore, photosynthesis, carbohydrate synthesis, nitrogen efficient utilization, and phytohormone signaling pathways are closely and intrinsically linked at the transcriptional level. These findings enhance our understanding of tillering in orchardgrass and perennial grasses, providing a new breeding strategy for improving forage biomass yield.

MORPHOLOGICAL CHARACTERIZATION OF ORCHARDGRASS (Dactylis glomerata L.) NATURALLY SPREAD IN EASTERN ANATOLIA, TÜRKIYE

Orchardgrass (Dactylis glomerata L.) is a cold-resistant, perennial and one of the main forage species of meadows and pastures. A total of 9 morphological traits were considered for the morphological characterization of the orchardgrass, which is naturally distribusted in the flora of 43 different locations in 8 provinces of the Eastern Anatolia of Türkiye. According to the analysis of variance; significant differences were determined between genotypes in terms of the morphological traits examined. These differences resulted in a high degree of phenotypic variation. In addition, correlation coefficient analysis showed a significant (P<0.01) and positive relation between most of the traits examined. The highest correlation coefficient was between plant height and peduncle length (0.864**), flag leaf length and flag leaf width (0.765**), flag leaf length and panicle length (0.734**) The first five Principal components (PCA) explained 70.31 % of the total variation in orchardgrass genotypes. The highest plant height and maximum number of tillers, which are important for grass yield and reproduction, were determined in M75 (77.57 cm) and R163 (27.85 per/plant) respectively. The high morphological variation among orchardgrass genotypes indicates the existence of a rich genetic population and can be considered as breeding material. Keywords: Türkiye, Eastern Anatolia, morphological characterization, phenotypic variation, Dactylis glomerata, orchardgrass.

Doğu Anadolu Habitatlarından Domuz ayrığı (Dactylis glomerata L.) Türlerinin Moleküler Çeşitliliğinin ve Dağılımının Analizinde Buğday SSR Markerlerinin Uygulanabilirliği

Türkiye is one of the world's nations with the greatest flora diversity in different plants. Moreover, it possesses a high level of plant genetic diversity. Orchardgrass (Dactylis glomerata L.) is one of the most important fodder species used during cool seasons since it is a hardy and perennial plant. The identification of Orchardgrass cultivars is essential for maximizing cultivar utilization, and safeguarding breeders' intellectual property. Dactylis glomerata L. is an allogamous, variable, monospecific genus with multiple subspecies distinguished by morphology, chromosomal count, and distribution. This genus has a single species, Dactylis glomerata L, which is comprised of multiple subspecies whose traits have not been exhaustively characterized. Using DNA assays that evaluated the transferability of nine SSR primers designed for wheat loci, the genetic diversity of 44 orchardgrass genotypes from eight naturally distributed locales in the Eastern Anatolia Area of Türkiye was calculated. On average, 6.78 alleles were discovered for each of the nine SSR primers, for a total of 61 alleles. A total of 54 polymorphic alleles were identified, with an average of 6.78 per primer. Polymorphism information content (PIC) values ranged from 0.320 (WMC96) to 0.626% (XBARC187). The average polymorphism rate of 88.89% suggests a high amount of genetic diversity among all studied genotypes. The average expected heterozygosity (He) ranged between 0.178 (Ağrı) to 0.882 (Erzurum). The genetic separation ranged from 0.01 to 0.66. In conclusion, our findings indicate that the Dactylis glomerata L genotypes gathered in Eastern Anatolia are a rich source of genetic variability, supplying a vast array of genetic material for orchardgrass breeding efforts.

Proteomic and physiological responses of contrasting two different heat-resistant orchardgrass genotypes to heat stress

As an important forage crop worldwide, the growth and productivity of orchardgrass are greatly impacted by high temperatures. However, little information is known about how orchardgrass proteomic changes under heat conditions. Therefore, the present study investigated the proteomics and physiological changes in 667 [AKZ-NRGR667 (heat-tolerant)] and 7602 [PI237602 (heat-sensitive)] under heat stress (40/35 °C). In addition, the responses of translational regulating of heat stress in orchardgrass were analyzed through proteomic changes using the tandem mass tags (TMT) technique. Together, 410 differentially expressed proteins (DEPs) were identified from two orchardgrass genotypes under heat at 24 h. Proteomics analyses indicated that proteins related to substance metabolism, photosynthesis, and heat shock proteins (HSPs) were differentially expressed under heat stress and control conditions. Moreover, a large proportion of HSPs were expressed in the heat-tolerant genotype as compared to the heat-sensitive genotype. In conclusion, genotype 667 has higher adaptability and repairing capability due to stronger heat tolerance capacity that can make it more suited to sustaining its survival and growth than genotype 7602. These findings can provide the basis for genetic improvements in orchardgrass and other crops facing high-temperature stress or heat environment that may lead to heat resistance or tolerance.

Comparative transcriptome analyses reveal different mechanism of high- and low-tillering genotypes controlling tiller growth in orchardgrass (Dactylis glomerata L.)

BackgroundTillering is an important agronomic trait underlying the yields and reproduction of orchardgrass (Dactylis glomerata), an important perennial forage grass. Although some genes affecting tiller initiation have been identified, the tillering regulatory network is still largely unknown, especially in perennial forage grasses. Thus, unraveling the regulatory mechanisms of tillering in orchardgrass could be helpful in developing selective strategies for high-yield perennial grasses. In this study, we generated high-throughput RNA-sequencing data from multiple tissues of tillering stage plants to identify differentially expressed genes (DEGs) between high- and low-tillering orchardgrass genotypes. Gene Ontology and pathway enrichment analyses connecting the DEGs to tillering number diversity were conducted.ResultsIn the present study, approximately 26,282 DEGs were identified between two orchardgrass genotypes, AKZ-NRGR667 (a high-tillering genotype) and D20170203 (a low-tillering genotype), which significantly differed in tiller number. Pathway enrichment analysis indicated that DEGs related to the biosynthesis of three classes of phytohormones, i.e., strigolactones (SLs), abscisic acid (ABA), and gibberellic acid (GA), as well as nitrogen metabolism dominated such differences between the high- and low-tillering genotypes. We also confirmed that under phosphorus deficiency, the expression level of the major SL biosynthesis genes encoding DWARF27 (D27), 9-cis-beta-carotene 9′,10′-cleaving dioxygenase (CCD7), carlactone synthase (CCD8), and more axillary branching1 (MAX1) proteins in the high-tillering orchardgrass genotype increased more slowly relative to the low-tillering genotype.ConclusionsHere, we used transcriptomic data to study the tillering mechanism of perennial forage grasses. We demonstrated that differential expression patterns of genes involved in SL, ABA, and GA biosynthesis may differentiate high- and low-tillering orchardgrass genotypes at the tillering stage. Furthermore, the core SL biosynthesis-associated genes in high-tillering orchardgrass were more insensitive than the low-tillering genotype to phosphorus deficiency which can lead to increases in SL biosynthesis, raising the possibility that there may be distinct SL biosynthesis way in tillering regulation in orchardgrass. Our research has revealed some candidate genes involved in the regulation of tillering in perennial grasses that is available for establishment of new breeding resources for high-yield perennial grasses and will serve as a new resource for future studies into molecular mechanism of tillering regulation in orchardgrass.

A genetic view on the role of prolonged drought stress and mating systems on post-drought recovery, persistence and drought memory of orchardgrass (Dactylis glomerata L.)

The consequences of recurrent drought events compared with a single drought and its interaction with deliberate selfing, compared with open-pollination on post-stress recovery, persistence, and drought memory, are not understood in orchardgrass (Dactylis glomerata L.). A long term study was started by creating 25 selfed (S1) and 25 open-pollinated progeny of orchardgrass in 2012. Populations were studied in the field, applying a normal and a recurrent drought stress environment for 4 years (2013–2016). In 2016, after the first harvest (June), watering was withheld in both moisture environments for 2 months and then plants were re-watered and evaluated for post-drought recovery and drought memory. On average, open pollination caused higher forage yield in the second and third years; while, in the first and fourth years, there was no significant difference. Obligate selfing reduced persistence of genotypes but did not affect recovery after prolonged drought. The early flowering genotypes had more plant productivity, yield stability, persistence, and drought tolerance, and were also capable of more regrowth and recovery. The results showed that genotypes of orchardgrass constantly performed differently under periodic drought as compared to prolonged drought stress. Moreover, there were significant genetic variations between genotypes in terms of stress memory.

Elit Domuz Ayrığı (Dactylis glomerata L.) Genotiplerinde Genetik Çeşitliliğin SSR Markörleri ile Belirlenmesi

Domuz ayrığı (Dactylis glomerata L.) yaygın olarak yetiştiriciliği yapılan, ekonomik açıdan önemli çok yıllık bir buğdaygil yem bitkisidir. Bu araştırma, Ege Tarımsal Araştırma Enstitüsü yem bitkileri ıslah programı kapsamında geliştirilen elit domuz ayrığı klonlarının akrabalık derecelerini ve genetik çeşitliliğini belirlemek amacıyla yürütülmüştür. Çalışmada 32 genotip ve 24 SSR primeri kullanılmıştır. Moleküler analiz sonucunda SSR primerleri toplamda 126 allel üretmiştir. Allel sayısı 3 ila 7 arasında değişmiş ve lokus başına düşen ortalama allel sayısı 5,25 olarak bulunmuştur. Elde edilen allel büyüklükleri ise 101 bp ile 354 bp arasında değişmiş ve polimorfizm oranı her primer için %100 olarak gerçekleşmiştir. Bireyler arasında uzaklık derecesi Jaccard genetik uzaklık katsayısı kullanılarak elde edilmiş ve 0,21 ile 0,84 arasında değişmiş ve genetik çeşitlilik seviyesi yüksek bulunmuştur. Genotiplerden elde edilen 126 allelin 28‘nin nadir alleller olduğu ortaya çıkmıştır. Jaccard genetik uzaklık katsayısı kullanılarak yapılan neighbor-joining analizi sonucunda oluşturulan dendrogram 3 ana gruba ayrılmıştır. A grubu en büyük grubu oluşturmuş ve bünyesinde 15 genotip barındırmıştır. B grubu orijini aynı bölge olan 13 genotiple ikinci büyük grubu oluşturmuştur. C grubu ise en küçük grup olup orijini Türkiye‘nin kuzeyi olan genotipleri barındırmıştır. Moleküler analizler domuz ayrığı genotiplerinin önemli derecede genetik varyasyon taşıdığı ve ıslah programı için değerli kaynaklar olduğu ortaya çıkmıştır. Bunlara ek olarak, SSR tekniğinin domuz ayrığı genotiplerini moleküler olarak tanımlamada oldukça uygun ve etkili bir teknik olduğu sonucuna varılmıştır.

Genetic variation in an orchardgrass population promises successful direct or indirect selection of superior drought tolerant genotypes

AbstractImprovement in drought tolerance is an important component of forage grass breeding. To assess the potential of selecting drought tolerant genotypes of orchardgrass, a polycross population was created in 2010 and evaluated in the field under normal and drought stress conditions during 2011–2013. Drought stress reduced performance in forage yield, growth characteristics, and most of the physiological traits measured, but increased carotenoid content, proline content, and the chlorophyll a/b ratio. High estimates of narrow‐sense heritability for chlorophyll and carotenoid content, as well as forage yield components, indicated that phenotypic selection would be successful in achieving genetic progress. Indirect selection to improve forage yield under drought stress conditions was efficient through selecting for chlorophyll a, chlorophyll b, total chlorophyll and carotenoid content. These physiological traits were also significantly associated with drought tolerance index. Overall, families 5, 7, 8, 13, 14 and 24 with high stress tolerance index values and high forage yield under both water conditions were identified as suitable families for breeding drought adaptive varieties.

Physiological responses of drought tolerance in orchardgrass (Dactylis glomerata) in association with persistence and summer dormancy

The genetic basis of physiological responses to drought and its association with productivity, persistence and summer dormancy is not clear in orchardgrass (Dactylis glomerata L.). Thirty-six orchardgrass genotypes were evaluated under water stress and non-stressed conditions during 2 years (2013–14). High genotypic variation was observed for all of the agronomic and physiological traits. Water stress reduced dry matter yield, relative water content and chlorophyll content while significantly increasing carotenoids, water-soluble carbohydrates, proline and chlorophyll a : b ratio. The results indicated that carotenoids and proline accumulation could not be used for discriminating drought-tolerant genotypes of orchardgrass, whereas water-soluble carbohydrates may be used to achieve this purpose. Moreover, the results showed that the stable genotypes that have lower changes in productivity from normal to water-stress environments also have more persistence. No association was found between summer dormancy and drought tolerance measured by both physiological and yield-based drought-tolerance indices. Some of the drought-tolerant genotypes had relatively high persistence and better autumn recovery, a characteristic useful for the development of new synthetic varieties.

Root characteristic system improves drought tolerance in orchardgrass

AbstractPlant genotypes with higher drought tolerance through improved root characteristics are poorly studied in orchardgrass. In the current research, 30 orchardgrass genotypes were polycrossed and the resulting half‐sib families evaluated under both normal and water stress environments. Under water stress conditions, values for most root traits decreased at 0–30 cm soil depth, while at 30–60 cm depths, the root length (RL), root area (RA), root volume, percentage of root dry weight (RDW) and the ratio of root to shoot were increased. We identified drought‐tolerant genotypes with a high combining ability for root characteristics and a high yield potential. High estimates of heritability as well as genetic variation for root traits indicated that phenotypic selection would be successful in order to achieve genetic progress. Indirect selection to improve dry matter yield was most efficient when selecting for RL and RDW under water stress conditions. Significant associations between a drought tolerance index and RL, RA and root volume confirmed the importance of these traits in conferring drought tolerance of orchardgrass.

Genetic Analysis of Stability in Poly‐Crossed Populations of Orchardgrass

Development of synthetic varieties is the most common breeding method in cross‐pollinated grasses. In these plants estimation of general combining ability (GCA) as well as the amount of interaction between additive effects and environment (AE) is of paramount importance. There is a lack of knowledge in orchardgrass (Dactylis glomerata L.) about the effect of genetic and stability analysis using poly‐crossed mating system. Half‐sib families derived from polycross of 25 orchardgrass genotypes were evaluated under two moisture environments (normal and drought stress) in the field during 5 yr (2010–2014). High genotypic variation was observed among families. The results showed that additive main effects and multiplicative interaction (AMMI) analysis along with regression method were useful in selection for plant biomass improvement where additive × environment interactions are present. Some genotypes were identified as the most stable across the environments as well as having high GCA for plant biomass. The results indicated that finding parental genotypes for synthetic varieties which can transmit both high plant biomass and stability is possible in orchardgrass.

Analysis of seed production and its association with forage production and agronomic traits in orchardgrass (Dactylis glomerata) under different moisture conditions

Genetic analysis of seed production and the effect of water stress on seed and forage production have not been addressed simultaneously in orchardgrass (Dactylis glomerata L.). Thirty-six genotypes of orchardgrass were clonally propagated and evaluated in the field under two moisture environments (normal and water stress) during 3 years (2013–15). A high degree of variation was observed among genotypes for all of the measured traits. Water stress had a negative effect on seed weight per plant and dry matter biomass per plant, and it reduced genotypic variation for most of the traits. A significant and positive correlation was found between seed weight per plant and dry matter biomass per plant, which suggested that simultaneous selection for both traits is possible in normal as well as water-stress environments. The results also indicated that traits explaining seed and forage production variability were not exactly the same in water-stress and non-stress environments. Therefore, indirect selection based on seed weight and dry matter biomass components under normal and water-stress conditions may result in genotypes with different performances. In both normal and water-stress environments, some genotypes were identified as superior with respect to high seed weight and dry matter biomass per plant. These genotypes can be used for further studies to improve seed weight and dry matter biomass per plant, simultaneously.

Selection for productivity, persistence and drought tolerance in orchardgrass

This study was aimed to evaluate genetic diversity for drought tolerance and persistency of Iranian and foreign germplasm of orchardgrass. Thirty six genotypes of orchardgrass were clonally propagated and grown in the field under two moisture environments (normal and drought stress) for 3 years (2013–2015). High genotypic variation was observed among genotypes for all the measured traits, indicating a high potential for improving traits. Drought stress had negative effects on most of the measured traits and reduced genotypic variation. Low heritability for forage yield (average 21 %) suggested that indirect selection based on components of forage yield which had moderate to high heritabilities and high correlation with yield would be more effective. However, the order of priority of these components and their direct and indirect effects was different for normal and drought stress conditions. This suggested that indirect selection for development of high yielding drought-tolerant varieties should be performed under non-stress environment with a specific model. The results of principal component analysis showed that there was a negative relationship between phenological traits (days to ear emergence and days to anthesis) with the traits related to persistency and yield production. This indicates that selection for earliness in orchardgrass can improve productivity and persistency in orchardgrass. Contrasting genotypes were identified by biplot method that is useful for development of genetic populations for breeding studies of drought tolerance and persistency in orchardgrass.

Identifying differentially expressed genes under heat stress and developing molecular markers in orchardgrass (Dactylis glomerata L.) through transcriptome analysis.

Orchardgrass (Dactylis glomerata L.) is a long-lived, cool-season forage grass that is commonly used for hay production. Despite its economic importance, orchardgrass genome remains relatively unexplored. In this study, we used Illumina RNA sequencing to identify gene-associated molecular markers, including simple sequence repeats (SSRs) and single nucleotide polymorphisms (SNPs), as well as heat stress-induced differentially expressed genes (DEGs) in two orchardgrass genotypes, 'Baoxing' (heat resistant) and '01998' (heat susceptible). Approximately 163 million high-quality trimmed reads were generated from 207 million raw reads using the Illumina HiSeq 2000 platform. A total of 126,846 unigenes were obtained after de novo assembly of the trimmed reads, and 40,078 unigenes were identified as coding sequences (CDSs). Based on the assembled unigenes, 669,300 high-quality SNPs, including 416,099 transitions and 257,736 transversions, were contained in 75,875 unigenes. In addition, a total of 8475 microsatellites were detected in 7764 unigenes. When placed under heat stress, the total number of DEGs in 'Baoxing' (3527) was higher than in '01998' (2649), indicating that in comparison with heat-susceptible '01998', heat-resistant 'Baoxing' seems to have more unigenes that respond to heat stress. The high-throughput transcriptome sequencing of orchardgrass under heat stress provides useful information for gene identification and for the development of SNP and SSR molecular markers. The comparison of DEGs under different periods of heat stress allowed us to identify a wealth of candidate DEGs that can be further analysed in order to determine the genetic mechanisms underlying heat tolerance in orchardgrass.

Genetic analysis of seed related traits in Orchardgrass (Dactylis glomerata) under normal and drought stress conditions

In forage grasses, knowledge about genetic analysis of seed production and its association with related traits under water deficit condition is very limited. Half sib families derived from polycross of 25 Orchardgrass genotypes were evaluated under normal and drought stress environments in the field during 2012 and 2013. Results showed that drought stress had negative effect on seed yield and reduced genotypic variation of measured traits. High genotypic variation was observed among families for seed yield and its components indicating high potential for improving these traits through targeted selection in breeding programs. Narrow sense heritability (\(h_{n}^{2}\)) ranged from 0.23 (flag leaf weight) to 0.77 (day to anthesis) and were moderately high for plant seed weight (0.46). Moderate to high heritability for seed yield components indicated that phenotypic selection for these traits can be successful. Seed yield had positive correlation with ear weight per plant, 1,000-seed weight, number of ear per plant, number of seed per panicle and seed weight in panicle. High association between seed yield and some seed yield components (especially number of ear per plant and 1,000-seed weight) as well as the high heritability of these traits indicated that indirect selection, based on seed yield components, would be more effective to improve seed yield of orchardgrass in both normal and drought stress environments.

Osmolyte accumulation, antioxidant enzyme activities and gene expression patterns in leaves of orchardgrass during drought stress and recovery

AbstractOrchardgrass (Dactylis glomerata L.) grows on marginal soils that could be frequently subjected to water‐deficit conditions. Mechanisms of grass plants in response to drought stress and rewatering remain largely unknown. The study was designed to investigate the different physiological and molecular responses of two genotypes of orchardgrass (drought‐tolerant ‘Baoxing’ and drought‐sensitive ‘01998’) to drought stress and rewatering. The ‘Baoxing’ and ‘01998’ were exposed to drought stress for 24 and 21 days in a growth chamber, respectively, allowing the leaf relative water content of both genotypes to drop to the same level (20%). ‘Baoxing’ exhibited higher net photosynthetic rate, free proline content, total soluble sugar (TSS) content and ornithine aminotransferase activity as well as lower electrolyte leakage compared with ‘01998’. After rewatering, ‘Baoxing’ recovered more rapidly in all parameters than ‘01998’ except for TSS. In addition, significantly higher activities of superoxide dismutase (SOD), catalase and guaiacol peroxidase (POD) as well as lower malondialdehyde levels were observed in the ‘Baoxing’ when compared with the ‘01998’ under drought stress and rewatering. Maintenance of higher transcripts levels of SOD and POD in ‘Baoxing’ suggests that SOD and POD could be involved in scavenging oxidative stress‐induced reactive oxygen and removing hydrogen peroxide in orchardgrass through changes in the level of gene expression. Combined with antioxidant enzyme activity and gene expression levels, our results indicate that POD could play critical roles in recovery from drought damages. The results indicated both osmolyte accumulation and antioxidant enzymes could contribute to a better drought tolerance of ‘Baoxing’ than ‘01998’.

Feasibility of Seed Production from Nonflowering Orchardgrass

ABSTRACTNonflowering or sparse flowering orchardgrass (Dactylis glomerata L.) would greatly simplify management of intensive rotational grazing systems. Our objective was to quantify seed production on nonflowering orchardgrass clones selected in cold‐winter climates, but grown for seed in mild‐winter climates. We evaluated 98 orchardgrass clones for seed production traits at four locations. Most plants (∼92%) flowered at the three northern locations, but only 38% flowered at Parlier, which may have a winter insufficiently cold for adequate floral induction and vernalization. Mean panicle number was lowest (11%) for plants selected at the location with the warmest winter conditions, and highest (37%) for plants selected at the location with the coldest winter conditions. These results confirm our expectations that the most desirable plants (nonflowering under cold winters and normal flowering under mild winters) should arise from selection under more severe winters. Selection for nonflowering under mild winter conditions simply leads to nonflowering plants under all conditions. These results demonstrate that individual orchardgrass genotypes are capable of dual phenotypic expression, flowering in mild‐winter climates or expressing the nonflowering trait in cold‐winter climates and that the expression of this trait depends on both the selection and evaluation location.

Anticytokinin effects on in vitro response of embryogenic and nonembryogenic genotypes of Dactylis glomerata L.

The effect of triazine and carbamate type of anticytokinins on in vitro response of embryogenic and nonembryogenic genotypes of orchardgrass (Dactylis glomerata L.) was studied. Both compounds stimulated callus production. Anticytokinins influenced both the efficiency of somatic embryogenesis and frequency of embryoid formation.

Water Requirement of Selected Genotypes of Orchardgrass, Dactylis glomerata L.1

Agronomy JournalVolume 45, Issue 12 p. 622-625 Article Water Requirement of Selected Genotypes of Orchardgrass, Dactylis glomerata L.1 Wesley Keller, Wesley Keller Geneticist, U. S. Dept. of Agriculture, Logan, Utah. The writer wishes to express appreciation to Dr. Sterling A. Taylor for helpful suggestions in planning the study, and to Prof. D. C. Tingey who read the manuscript and offered helpful suggestions in the interpretation of the data.Search for more papers by this author Wesley Keller, Wesley Keller Geneticist, U. S. Dept. of Agriculture, Logan, Utah. The writer wishes to express appreciation to Dr. Sterling A. Taylor for helpful suggestions in planning the study, and to Prof. D. C. Tingey who read the manuscript and offered helpful suggestions in the interpretation of the data.Search for more papers by this author First published: 01 December 1953 https://doi.org/10.2134/agronj1953.00021962004500120010xCitations: 4 1 Contribution of the Division of Forage Crops & Diseases, BPISAE, ARA, U. S. Dept. of Agriculture, in cooperation with the Utah Agr. Exp. Sta. and the Intermountain Forest and Range Exp. Sta. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume45, Issue12December 1953Pages 622-625 RelatedInformation