Peduncle breaking resistance: a potential selection criterion to improve lodging tolerance in oat

Breeding for tolerance to lodging is an objective, but also a challenge, in oat (Avena sativa L.) breeding programs. A widely adopted method to assess breeding lines for tolerance to lodging is based on visual scoring of plant standability (1 = standing upright; 9 = completely lodged). The lack of sufficient lodging pressure due to weather or growing conditions often renders the visual scoring method ineffective. We present an alternative approach that allows selection for tolerance to stem lodging by screening for peduncle strength in the absence of lodging pressure. This approach also provides objective selection of lodging tolerance using a quantitatively measurable plant trait rather than subjective scoring of the lodged plants. Stem structural and mechanical properties of six oat cultivars with varying levels of lodging tolerance were tested at field experiments over 3 site-years under three nitrogen rates. Results suggested peduncle breaking resistance (PBR), measured below the panicle, as a potential selection criterion for stem strength and therefore lodging tolerance. Significant genetic variation among oat cultivars (p < 0.01) was observed for PBR, which was significantly correlated with the strength of all lower internodes in all environments (R2 > 0.73, p ≤ 0.05). This suggests that PBR provides a good estimation of the whole culm strength. Phenotyping of PBR can be easily integrated into breeding programs because of the ease of sampling and rapid measurement.

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Numeric codes for developmental stages of oat apex in the growing conditions of Southern Finland

Agricultural and Food Science ◽

10.23986/afsci.72655 ◽

1993 ◽

Vol 2 (4) ◽

pp. 329-336

Author(s):

Pirjo Peltonen-Sainio ◽

Tiina Pekkala

Keyword(s):

Field Experiments ◽

Developmental Stages ◽

Ratio Scale ◽

Degree Days ◽

Breeding Lines ◽

Oat Cultivars ◽

Growing Conditions ◽

The University

Scales that categorize the development of cereal apex have been introduced by several authors. Daylength markedly affects the rate of apex organogenesis and, hence, numeric codes for developmental stages of apices introduced for lower latitudes cannot be used in Finland without modifying them into a ratio scale. The present study introduces numeric codes that categorize the 22 developmental stages of oat (Avena saliva L.) apex in the growing conditions of Southern Finland. Field experiments, including 14 oat cultivars and six breeding lines that differ in the duration of the period from initiation of double ridges to pollination, were carried out at the Viikki Experimental Farm of the University of Helsinki (60°13’N) for two years. The numeric codes were established by relating them to cumulated degree days (CDD). This study showed that when estimating the developmental stages of oat apex by calculating CDD from sowing, the error of estimation was ±1 stage unit at the most.

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Early stage selection for commercial cane sugar (CCS) in sugarcane clones: effects of time of sampling and irrigation

Australian Journal of Agricultural Research ◽

10.1071/ar02110 ◽

2003 ◽

Vol 54 (4) ◽

pp. 389 ◽

Cited By ~ 7

Author(s):

Phillip A. Jackson ◽

Terry E. Morgan

Keyword(s):

Field Experiments ◽

Clonal Selection ◽

Early Stage ◽

Sugar Content ◽

Selection Criterion ◽

Cane Yield ◽

Physiological Basis ◽

Breeding Programs ◽

Sugarcane Breeding ◽

Selection For

Commercially recoverable sugar content in sugarcane (CCS, expressed as a percentage) is a key selection criterion in sugarcane breeding programs. In some sugarcane breeding programs there may be significant operational advantages in measuring CCS early in the crop growth cycle, well before commercial harvesting would normally commence, and in restricting growth by withholding irrigation to reduce cane yield and lodging. Two field experiments were conducted to investigate these effects. The experiments included clones representative of genotypes routinely assessed in the earliest stages of clonal selection in breeding programs. Differences among genotypes for CCS were expressed early when cane had very low CCS (in February or March), and then rates of increase in CCS following that time were similar in most genotypes. Therefore, time of sampling had little effect on ranking of genotypes for CCS, and selection for high CCS could be effective early in the year. Irrigation regime also had little effect on ranking of the clones for CCS, indicating that mild water stress could be imposed with no adverse effect on selection results. The results are discussed in relation to optimising selection procedures and systems in early stage selection trials in sugarcane breeding programs, and better understanding the physiological basis of genetic variation in CCS.

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Characterization of the Reproductive Mode in Guayule In Vitro

HortScience ◽

10.21273/hortsci.33.3.483a ◽

1998 ◽

Vol 33 (3) ◽

pp. 483a-483

Author(s):

Roy N. Keys ◽

Dennis T. Ray ◽

David A. Dierig

Keyword(s):

Field Experiments ◽

Reproductive Mode ◽

Dichlorophenoxyacetic Acid ◽

Initial Field ◽

Breeding Lines ◽

Reproductive Modes ◽

Desert Southwest ◽

2,4 Dichlorophenoxyacetic Acid

Guayule (Parthenium argentatum Gray, Asteraceae) is a latex-producing perennial desert shrub that is potentially of economic importance as an industrial crop for the desert Southwest. It is known to possess complex reproductive modes. Diploids are predominantly sexual and self-incompatible, while polyploids show a range of apomictic potential and self-compatibility. This paper describes the development of a relatively rapid and simple technique for characterizing reproductive modes of breeding lines of P. argentatum. Initial field experiments were based on an auxin test used successfully to characterize reproductive mode in the Poaceae. The application of 2,4-dichlorophenoxyacetic acid inhibited embryo formation in P. argentatum, but this was not the case with other auxins tested. Results of field experiments were ambiguous because: 1) the floral structure of P. argentatum is such that auxins might not have penetrated to the ovules, and 2) there was potential self-fertilization by pollen released within isolation bags. Therefore, in vitro culture of flower heads was tested because it provided much better control of environmental conditions, growth regulator application, and pollen release. Auxin alone, or in combination with gibberellic acid or kinetin, inhibited parthenogenesis in vitro. Embryo production did not vary using two substantially different nutrient media. In vitro flower head culture using a (Nitsch and Nitsch) liquid nutrient medium without growth regulators, enabled characterization of the reproductive mode of seven breeding lines, ranging from predominantly sexual to predominantly apomictic. The results of this technique were substantiated using RAPD analyzes of progeny arrays from controlled crosses.

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Field Evaluations of Leaf Spot Resistance and Yield in Peanut Genotypes in the United States and Bolivia

Plant Disease ◽

10.1094/pdis-06-10-0454 ◽

2011 ◽

Vol 95 (3) ◽

pp. 263-268 ◽

Cited By ~ 4

Author(s):

S. K. Gremillion ◽

A. K. Culbreath ◽

D. W. Gorbet ◽

B. G. Mullinix ◽

R. N. Pittman ◽

...

Keyword(s):

United States ◽

Disease Resistance ◽

Leaf Spot ◽

Field Experiments ◽

Disease Incidence ◽

The United States ◽

Yield Potential ◽

Cercospora Arachidicola ◽

Breeding Lines ◽

Progress Curve

Field experiments were conducted in 2002 to 2006 to characterize yield potential and disease resistance in the Bolivian landrace peanut (Arachis hypogaea) cv. Bayo Grande, and breeding lines developed from crosses of Bayo Grande and U.S. cv. Florida MDR-98. Diseases of interest included early leaf spot, caused by the fungus Cercospora arachidicola, and late leaf spot, caused by the fungus Cercosporidium personatum. Bayo Grande, MDR-98, and three breeding lines, along with U.S. cvs. C-99R and Georgia Green, were included in split-plot field experiments in six locations across the United States and Bolivia. Whole-plot treatments consisted of two tebuconazole applications and a nontreated control. Genotypes were the subplot treatments. Area under the disease progress curve (AUDPC) for percent defoliation due to leaf spot was lower for Bayo Grande and all breeding lines than for Georgia Green at all U.S. locations across years. AUDPC for disease incidence from one U.S. location indicated similar results. Severity of leaf spot epidemics and relative effects of the genotypes were less consistent in the Bolivian experiments. In Bolivia, there were no indications of greater levels of disease resistance in any of the breeding lines than in Bayo Grande. In the United States, yields of Bayo Grande and the breeding lines were greater than those of the other genotypes in 1 of 2 years. In Bolivia, low disease intensity resulted in the highest yields in Georgia Green, while high disease intensity resulted in comparable yields among the breeding lines, MDR-98, and C-99R. Leaf spot suppression by tebuconazole was greater in Bolivia than in the United States. This result indicates a possible higher level of fungicide resistance in the U.S. population of leaf spot pathogens. Overall, data from this study suggest that Bayo Grande and the breeding lines may be desirable germplasm for U.S. and Bolivian breeding programs or production.

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Response of Early, Medium, and Late Maturing Peanut Breeding Lines to Field Epidemics of Tomato Spotted Wilt

Peanut Science ◽

10.3146/i0095-3679-26-2-8 ◽

1999 ◽

Vol 26 (2) ◽

pp. 100-106 ◽

Cited By ~ 32

Author(s):

A. K. Culbreath ◽

J. W. Todd ◽

D. W. Gorbet ◽

S. L. Brown ◽

J. A. Baldwin ◽

...

Keyword(s):

High Oleic Acid ◽

Breeding Programs ◽

Breeding Lines ◽

High Oleic ◽

Tomato Spotted Wilt ◽

Arachis Hypogaea L ◽

Early Maturing ◽

Late Maturity ◽

Field Plots ◽

Maturity Groups

Abstract Epidemics of tomato spotted wilt, caused by tomato spotted wilt Tospovirus (TSWV), were monitored in field plots of runner-type peanut (Arachis hypogaea L.) cultivars Georgia Green and Georgia Runner and numerous breeding lines from four different breeding programs as part of efforts toward characterizing breeding lines with potential for release as cultivars. Breeding lines were divided into early, medium and late maturity groups. The tests were conducted near Attapulgus, GA and Marianna, FL in 1997 and in Tifton, GA and Marianna, FL in 1998. Epidemics in some early and medium maturing breeding lines, including some genotypes with high oleic acid oil chemistry, were comparable to those in Georgia Green, the cultivar most frequently used in the southeastern U.S. for suppression of spotted wilt epidemics. No early maturing breeding lines had lower spotted wilt final intensity ratings or higher yields than Georgia Green. However, spotted wilt intensity ratings in some late maturing lines and a smaller number of medium maturing lines were significantly lower than those of Georgia Green. Several of those lines also produced greater pod yields than Georgia Green. Results from these experiments indicated that there is potential for improving management of spotted wilt though development of cultivars that suppress spotted wilt epidemics more than currently available cultivars. There was no indication that differences in spotted wilt ratings corresponded to differences in numbers of thrips adults or larvae.

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Late Leaf Spot Severity and Yield of New Peanut Breeding Lines and Cultivars Grown Without Fungicides

Plant Disease ◽

10.1094/pdis-02-17-0165-re ◽

2017 ◽

Vol 101 (11) ◽

pp. 1843-1850 ◽

Cited By ~ 3

Author(s):

Brian S. Jordan ◽

Albert K. Culbreath ◽

Timothy B. Brenneman ◽

Robert C. Kemerait ◽

William D. Branch

Keyword(s):

Leaf Spot ◽

Vegetation Index ◽

Field Experiments ◽

Organic Production ◽

Canopy Reflectance ◽

Cercospora Arachidicola ◽

Early Season ◽

Late Leaf Spot ◽

Breeding Lines ◽

Width Measurements

Peanut (Arachis hypogaea) cultivars with resistance or tolerance to Cercospora arachidicola and/or Cercosporidium personatum, the causes of early and late leaf spot, respectively, are needed for organic production in the southeastern U.S. To determine the potential of new breeding lines for use in such production systems, field experiments were conducted in Tifton, GA, in 2014 and 2015 in which nine breeding lines and two cultivars, Georgia-06G and Georgia-12Y, were grown without foliar fungicide applications. In one set of trials, cultivar Georgia-12Y and most of the breeding lines evaluated had early season vigor ratings, early-season canopy width measurements, final plant populations, and pod yield that were greater than those of standard cultivar Georgia-06G. In those trials, final late leaf spot Florida scale ratings were lower and canopy reflectance measured as the normalized difference vegetation index (NDVI), was higher all the breeding lines than those of Georgia-06G. In another set of trials, two of those same breeding lines had final late leaf spot ratings similar to those of Georgia-12Y in 2014, whereas in 2015, six of those breeding lines had final leaf spot ratings that were lower than those of Georgia-12Y. Yields were similar for Georgia-12Y and all the breeding lines in the Gibbs Farm trials. Across years and breeding lines at the Lang Farm, the relationship between visual estimates of defoliation and NDVI was described by a two sector piecewise regression with NDVI decreasing more rapidly with increasing defoliation above approximately 89%. The utility of NDVI for spot comparisons among breeding lines appears to be limited to situations where there are differences in defoliation. Georgia-12Y and multiple breeding lines evaluated show potential for use in situations such as organic production where acceptable fungicides available for seed treatment and leaf spot control are limited.

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Potato cultivars vary in susceptibility to blackleg (Erwinia carotovora subsp atroseptica)

New Zealand Plant Protection ◽

10.30843/nzpp.2009.62.4847 ◽

2009 ◽

Vol 62 ◽

pp. 403-403

Author(s):

P.J. Wright ◽

J.A.D. Anderson

Keyword(s):

New Zealand ◽

Bacterial Growth ◽

Field Experiments ◽

Erwinia Carotovora ◽

Potato Cultivars ◽

Plant Food ◽

Breeding Lines ◽

Susceptibility To Infection ◽

Food Research ◽

Commercial Cultivars

Ten potato cultivars were tested for susceptibility to infection by Erwinia carotovora subsp atroseptica (Eca) the causal agent of blackleg over two maincrop seasons in 200506 and 200607 The pathogen was inoculated into seed tubers using toothpicks charged with undiluted bacterial growth Blackleg incidence was assessed 56 weeks after planting The field experiments clearly confirmed that potato cultivars vary significantly in susceptibility to blackleg Some New Zealand cultivars had a lower susceptibility to blackleg than current commercial cultivars The new Plant Food Research release Summer Delight in particular had an exceptional level of resistance and will be used as a parent in efforts to develop potato cultivars with lower blackleg susceptibility than current local commercial cultivars Routine screening of Plant Food Research breeding lines and cultivars will continue to be carried out over several seasons to confirm results presented here and to determine further blacklegresistant germplasm

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CHEMICAL COMPOSITION OF WHOLE GRAINS IN COMMON BEANS LANDRACES AND BREEDING GENOTYPES

HOLOS - ISSN 1807-1600 ◽

10.15628/holos.2015.1996 ◽

2015 ◽

Vol 2 ◽

pp. 81 ◽

Cited By ~ 1

Author(s):

Gilberto Antonio Peripolli Bevilaqua ◽

Iraja Ferreira Antunes

Keyword(s):

Nutritional Composition ◽

Whole Grain ◽

Breeding Programs ◽

Breeding Lines ◽

Manganese Zinc ◽

Nutritional Characteristics ◽

Calcium Magnesium ◽

The Common ◽

Iron Manganese ◽

Insoluble Fiber

The common bean has been object of breeding programs aiming the development of new cultivars adapted to varied production system and shown differentiated nutritional characteristics. Due a genetic diversity existent the landraces can be used directly for cropping, for present characteristics desirable. Little information exists about mineral content and other quality traits for those bean landraces. The aim of this paper was to verify the variability for grain nutricional caracters in breeding cultivars and landraces of bean from Rio Grande do Sul state, Brazil. The experiment was conducted in 2009/2010 in Experimental Station Cascata, of Embrapa Temperate Agriculture. In whole grain of 54 bean genotypes with black and no black coat were determined macroelements (nitrogen, phosphorus, potash, calcium, magnesium and sulfur), oligoelements (iron, manganese, zinc and cuprum), protein and ash content, insoluble fiber, digestive nutrient and antioxidant astragalina. The results shown that the landraces varieties presents nutritional composition of macro and oligoelements, fibers, protein and ash contents in whole grain similar than that of breeding lines and cultivars. The black coat grain from breeding programs showed better nutritional quality for macro and oligoelements content than coloured grain, highlighting TB 02-04 e TB 01-01. The landraces with coloured grains TB 02-26, TB 02-24 and TB 03-13 showed the high levels of astragaline.

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Variability assessment of productivity traits and quality of berries in the genetic collection of garden strawberry (Fragaria ananassa Duch.) in the Orenburg region

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/845/1/012015 ◽

2021 ◽

Vol 845 (1) ◽

pp. 012015

Author(s):

E V Aminova ◽

R R Salimova ◽

O E Merezhko

Keyword(s):

Field Experiments ◽

Sugar Content ◽

Climatic Conditions ◽

Soluble Solids ◽

Average Weight ◽

Marketable Yield ◽

Berry Quality ◽

Growing Conditions ◽

Productivity Potential

Abstract Nowadays the study of the interrelation of the genotype of strawberry plants in garden and climatic conditions is extremely relevant. Due to the various systems of genetic control and the modifying effects of growing conditions on the manifestation of quantitative traits, there is the need to assess the genotypic variability of economically valuable features, focused on the identification of genotypes characterized by stability and adaptive qualities in growing conditions. The study examined 15 varieties of garden strawberries of domestic and foreign selection. The field experiments and surveys were carried out according to the Program generally accepted in the Russian Federation and methodology for the variety study of fruit, berry and nut crops. We studied such features as the number of peduncles (pcs/bush), number of berries (pcs/bush), average weight of berries (g), total and marketable yield (g/bush), sugar content in berries, soluble solids and ascorbic acid. The purpose of this work was to assess the genotype-year interrelation in terms of the variability of productivity features and berry quality and to identify strawberry varieties with a stable genotype. As a result of two-way analysis of variance for the variety-year interrelation, the obtained values were 1.10-8.50 at standard Fst. - 1.24. Statistically important differences had indicators of productivity of a bush between the first and second clusters (t = 5.89 at p <0.01), the first and third (t = 15.83 at p <0.01), the second and third clusters (t = 8.13 at p <0.01), as well as the average berry weight between the first and third, second and third clusters (t = 15.50 and 6.99 at p <0.01, respectively). Significant differences in the value of the Euclidean distance were revealed for varieties Mishutka (54.5), Daryonka (54.5), Pervoklassnitsa (58) realizing their productivity potential in different years of cultivation.

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Digital imaging outperforms traditional scoring methods of spittlebug tolerance in Urochloa humidicola hybrids

10.1101/2020.10.13.338186 ◽

2020 ◽

Author(s):

Luis M. Hernandez ◽

Paula Espitia ◽

Valheria Castiblanco ◽

Juan A Cardoso

Keyword(s):

Correlation Coefficient ◽

Digital Imaging ◽

Digital Images ◽

Breeding Program ◽

Alternative Methods ◽

Screening Methods ◽

Plant Tolerance ◽

Scoring Method ◽

Plant Damage ◽

Visual Scoring

AbstractAmerican spittlebug complex (Hemiptera: Cercopidae) is a critical pest for existing Urochloa humidicola cultivars in the neotropical savannas. The U. humidicola breeding program of the International Center for Tropical Agriculture aims to increase tolerance to spittlebugs. To develop U. humidicola genotypes with superior tolerance to spittlebugs than existing cultivars, adequate screening methods ought to be deployed. Currently, visual scores of plant damage by spittlebugs is the standard method to screen for variation in plant tolerance. However, visual scoring is prone to human bias, is of medium throughput and relies of the expertise of well-trained personnel. In this study, we compared estimations of plant damage from two alternative methods (SPAD measurements and digital images) and visual scoring from an inexpert evaluator with the plant damage estimated from an expert. This information should instruct if different methods could be implemented in the U. humidicola breeding program. Time needed to evaluate damage was recorded for each method. Lin’s correlation coefficient, Pearson’s correlation coefficient and broad sense heritability values were also calculated. Overall, damage estimated from digital images showed the highest throughput (twice as fast as visual scoring from an expert); high correlations with visual scoring (r > 0.80, p < 0.0001); and heritability values for plant damage as good or better (> 0.7) than those obtained by visual scoring from an expert. Our results indicate that digital imaging is a phenotyping method that might improve the efficiency of breeding for increased tolerance to spittlebugs in U. humidicola.HighlightDigital imaging outperformed standard scoring method of spittlebug tolerance in Urochloa humidicola, suggesting that this method might improve the efficiency of breeding for such stress.

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