A rapid method to increase the number of F1 plants in pea (Pisum sativum) breeding programs.

In breeding programs, a large number of F2 individuals are required to perform the selection process properly, but often few such plants are available. In order to obtain more F2 seeds, it is necessary to multiply the F1 plants. We developed a rapid, efficient and reproducible protocol for in vitro shoot regeneration and rooting of seeds using 6-benzylaminopurine. To optimize shoot regeneration, basic medium contained Murashige and Skoog (MS) salts with or without B5 Gamborg vitamins and different concentrations of 6-benzylaminopurine (25, 50 and 75 µM) using five genotypes. We found that modified MS (B5 vitamins + 25 µM 6-benzylaminopurine) is suitable for in vitro shoot regeneration of pea. Thirty-eight hybrid combinations were transferred onto selected medium to produce shoots that were used for root induction on MS medium supplemented with α-naphthalene-acetic acid. Elongated shoots were developed from all hybrid genotypes. This procedure can be used in pea breeding programs and will allow working with a large number of plants even when the F1 plants produce few seeds.

Diversity of pea (Pisum sativum) accessions based on morphological data for sustainable field pea breeding in Argentina.

We characterized 13 accessions of dry peas of different origins from various growing regions in Argentina, based on three replications of 20 plants cultivated in 2009 and 2010 in a greenhouse, with the objective of selecting those with favorable characteristics for use in breeding programs. Significant differences were found for length and width of stipule and pod, length of the internodes and leaflets, plant height, total number of nodes, number of nodes at the first pod, number of days to flowering and to harvest, number of pods and seeds per pod, 100-seed weight and grain diameter, demonstrating a high degree of genetic variability. Phenotypic correlation analysis demonstrated that large pods produced more seeds per pod, but the seed weight decreased. Plants with smaller number of nodes in the first pod were more productive. Estimates of genotypic correlation coefficients indicated a strong inherent association among the different traits. Clustering methods grouped the accessions into five clusters. Cluster 5 included two accessions and showed the highest values for length and width of stipules (4.9 and 4.5 cm, respectively), length of leaflets (7.43 cm) and days to flowering (122.6), while cluster 3, with one accession, and cluster 4, with two accessions, showed the highest values for number of seeds per pod (3.78 and 4.39), number of pods per plant (5.33 and 5.70), length of pods (5.54 and 5.72 cm), and width of pods (1.21 and 1.20 cm, respectively). We conclude that accessions in clusters 3 and 4 would be useful for crosses with other cultivars in pea breeding programs.

Mejoramiento de arveja (Pisum sativum L): avances del programa de mejoramiento genético de la Universidad Nacional de Rosario / Pea (Pisum sativum L.) breeding: advances of the breeding program at Universidad Nacional de Rosario

RESUMEN En 2005 se inició un programa de mejoramiento de arveja para aumentar la producción en cantidad y calidad en la Facultad de Ciencias Agrarias (FCA), Universidad Nacional de Rosario (UNR). Los primeros pasos fueron reunir una colección activa de germoplasma de todo el mundo y analizar la variabilidad genética a través de rasgos morfo-agronómicos y moleculares. En 2014, el Instituto Nacional de Tecnología Agropecuaria (INTA) y la FCAUNR unieron esfuerzos para promover el desarrollo local de genotipos de arveja adaptados a la región. Este programa, utilizando metodologías convencionales, ha obtenido hasta el momento una nueva variedad comercial (Primogénita FCA-INTA) de color de cotiledón verde, semi-áfila, con alta adaptación a las condiciones agroecológicas locales y alto potencial de rendimiento. El mejoramiento genético, sin embargo, es un proceso lento. El desarrollo de nuevas variedades requiere una década o más utilizando metodologías tradicionales, por lo que se propusieron diferentes alternativas para la reducción de este período. Los haploides duplicados y el cultivo in vitro han sido algunas de las metodologías desarrolladas, sin embargo, en legumbres no se han podido implementar de manera eficiente en los programas de mejoramiento. En este contexto, Speed Breeding surge como una tecnología que permite incrementar la eficiencia de los programas, reduciendo los costos y el trabajo requerido.

ABSTRACT A pea breeding program to increase production in quantity and quality was started in 2005 in the College of Agrarian Sciences (FCA), National University of Rosario (UNR). The first steps were to gather an active collection of germplasm from around the world and to analyze genetic variability through morpho-agronomic and molecular traits in order to set objectives. In 2014, the National Institute of Agropecuarian Technology (INTA) and the FCAUNR, joined forces to unite inter-institutional efforts for promoting the local development of pea genotypes adapted to the region. This program, using conventional methodologies, has so far obtained a new commercial line (Primogénita FCA-INTA) of green cotyledons, semileafless, with high adaptation to local agro ecological conditions and high yield potential. Breeding, nevertheless, is a slow process. Developing new pea varieties usually takes a decade or more when using traditional methodologies; thus, different alternatives were proposed for the reduction of this period. Doubled haploids and in vitro culture have been some of the methodologies developed; in pulses, however, they have not been efficiently implemented in breeding programs. In this context, Speed Breeding emerges as a technology that allows increasing the efficiency of the programs, while reducing costs and the required labor.

Herramientas complementarias utilizadas en el programa de mejoramiento de arveja (Pisum sativum l.) de la Universidad Nacional de Rosario / Complementary tools utilized in the pea (Pisum sativum l.) breeding program at Universidad Nacional de Rosario

RESUMEN El mejoramiento convencional puede ser complementado mediante diferentes estrategias que incrementen la eficiencia de las metodologías y la tasa actual de aumento de los rendimientos a fin de satisfacer la demanda. El uso de marcadores moleculares con el objetivo de desarrollar mapas de ligamiento de la especie, el uso de Blup (Best Linear Unbiased Prediction) para una selección eficiente de progenitores a hibridar, el uso del cultivo in vitro para incrementar artificialmente el número de plantas F1 o el uso de fenotipificación digital para una eficiente caracterización digital que puede realizarse durante la regeneración periódica y rutinaria de accesiones en colecciones de germoplasma.

ABSTRACT Conventional breeding can be complemented by different strategies that increase the efficiency of the methodologies and the current rate of increase in yields in order to meet demand. The use of molecular markers with the aim of developing linkage maps of the species, the use of Blup (Best Linear Unbiased Prediction) for an efficient selection of progenitors to hybridize, the use of in vitro culture to artificially increase the number of F1 plants or the use of digital phenotyping for efficient digital characterization that can be performed during the periodic and routine regeneration of accessions in germplasm collections.

Aplicación de diferentes metodologías en el mejoramiento de lenteja (Lens culinaris Medik) / Application of different methodologies in lentil (Lens culinaris Medik) breeding

RESUMEN La lenteja (Lens culinaris Medik.) es una especie diploide autógama (2n=2x=14) perteneciente a la familia Fabaceae. Es uno de los cultivos más antiguos que se conocen, con 8.000 a 9.000 años de historia, y se encuentra entre los primeros domesticados en Medio Oriente. Las semillas tienen un alto valor nutricional. Este cultivo es un interesante sustituto del trigo en las rotaciones de cereales, pero su importancia es baja debido a la falta de buenas variedades con adaptación local. Uno de los principales problemas que enfrentan los mejoradores en nuestro país es la estrecha base genética del germoplasma cultivado y su bajo potencial de rendimiento. En 2004 se inició un programa de mejoramiento de lentejas para desarrollar nuevas variedades con adaptación a las condiciones predominantes en las áreas de cultivo de Argentina. El germoplasma se obtuvo del ICARDA (Centro Internacional de Investigación Agrícola en las Zonas Áridas) y de productores locales. Se utilizan métodos convencionales de mejoramiento basados en la hibridación y selección. Se han obtenido dos nuevas variedades, una del tipo macrosperma (Boyerito FCA) y la otra del tipo microsperma (Tacuarita FCA) mediante la aplicación de selección masal en poblaciones F2 provenientes de la hibridación de materiales seleccionados. Este programa complementa los métodos de mejora tradicional con técnicas biotecnológicas como la transgénesis, el uso de marcadores moleculares, el cultivo de embriones in vitro combinado con el método SSD para acortar el ciclo generacional, y el fenotipado digital.

ABSTRACT Lentil (Lens culinaris Medik.) is a self-pollinating diploid (2n=2x=14) species belonging to the Fabaceae family. It is one of the oldest crops known, with 8,000 to 9,000 years of history and it is among the earliest domesticates from the Near East Fertile Crescent. The seeds have high nutritional value. This crop is an interesting substitute to wheat in cereal rotations but its importance is low due to a lack of suitable varieties with local adaptation. Some of the major problems that Argentinian lentil breeders face are the narrow genetic base of the current cultivated germplasm and its low yield potential. A lentil breeding program was initiated in 2004 to develop new varieties with adaptation to prevalent conditions in growing areas of Argentina. Germplasm was obtained from ICARDA (International Center for Agricultural Research in the Dry Areas) and local producers. Conventional breeding methods using hybridization and selection are being carried out to develop improved varieties, broad the genetic base, and isolate superior recombinant inbred lines. Two new varieties have been obtained, one of the macrosperm type (Boyerito FCA) and the other of the microsperm type (Tacuarita FCA) through the application of mass selection in F2 populations from the cross of selected materials. This program complements traditional breeding methods with biotechnological techniques such as transgenesis, use of molecular markers, in vitro embryo culture combined with the SSD method to shorten the breeding time, and digital phenotyping.

[Value and limitations of scintigraphy of the hand in rheumatoid arthritis]. / Valore e limiti della scintigrafia della mano in corso di artrite reumatoide.

99mTc-polyphosphate joint imaging of the hand has been performed in 18 patients, with evidence of inflammatory joint disease, but without any significant radiographic lesions, which might be related to rheumatoid arthritis. The hand scans were compared to clinical and radiographic data. An year after, the same subjects were re-examined, with both the radionuclide imaging and radiography. Scintigraphy has been shown to be significantly more sensitive for detecting inflammatory joint disease than x-ray, especially in the early stage of rheumatoid arthritis. Although radionuclide imaging is non specific (activity is increased also in osteoarthritis, trauma, metabolic bone disease, infarction, etc.). Radiography is highly specific but relatively non sensitive.

Low birth weight in twins versus singletons: separate entities and different implications for child growth and survival.

The condition of low birth weight is compared in twins and in singletons in terms of birth weight distributions and with respect to factors such as the incidence of stillbirths, length of gestation, maternal age, parity, and legitimacy. In the light of demographic, biological, and developmental considerations, it is concluded that low birth weight in twins is a different condition from low birth weight in singletons and should be dealt with independently, especially in view of the different implications for child growth and survival.

Weight and height growth in twins and children born in the last decade.

Weight and height growth has been examined in 400 twins and 229 singletons born 1975-1985. Periodical measurements have been taken from 0 to 7 years of age. As compared to values obtained in a previous study of twins and singletons born 1960-1974, though limited to the first year of age, twins appear to continue to do worse than singletons in their growth. However, height values appear to have become higher in the first year of age in both twins and singletons born 1975-1985.

[Xeroradiographic study of rheumatoid arthritis hand (author's transl)]. / Importanza della xeroradiografia nello studio della mano del paziente affetto da artrite reumatoide.

The hands of 50 rheumatoid arthritis patients and 32 non-arthritis controls were studied with conventional x-ray and xeroradiography. The xeroradiograph and radiograph of each patient were compared, assessing the degree of subperiosteal erosion, loss of joint space, soft tissue thickening and joint deformity. Each metacarpophalangeal and proximal interphalangeal joint alterations were scored on a 0-3 scale. Comparison between xeroradiographic and radiographic techniques showed that osteoporosis was better documented on conventional x-ray while loss of joint space and synovial thickening on xeroradiographs. In conclusion, conventional x-ray study of rheumatoid arthritis hand is comparable with xeroradiographic one, even if not substitutable.

[Xeroradiography in the study of dysmetabolic arthropathies]. / La xeroradiografia nello studio delle artropatie dismetaboliche.

70 patients affected by methabolic joint diseases are reviewed. Xeroradiography has been performed in hand, foot and knee for studying soft tissue and bone lesions in 12 subjects affected by chronic gout and 5 by CPPD. Results show that xeroradiography is more effective than X-ray films in outlining soft tissue masses, especially little dystrophic meniscal calcifications, and initial lesions in bone.

[Polygraphic study of left ventricular function in severe hepatitis cirrhosis]. / Studio poligrafico della funzione ventricolare sinistra nella cirrosi epatica severa.

Systolic time intervals have been investigated in 26 subjects with severe liver cirrhosis. The patients were subdivided as follows: 15 with alcoholic cirrhosis; 11 with post-necrotic cirrhosis. Systolic time intervals were recorded and measured according to the Weissler's method. The left ventricular ejection time was significantly shortened due to the low systemic vascular resistance, while the pre-ejection period was unchanged, denoting preserved myocardial contractility. The isometric contraction time was also significantly shortened, thus confirming a good myocardial response to increased pre-load due to hyperdynamic state. The cardiac performance as assessed by systolic time intervals, is unchanged in hepatic cirrhosis.

[The hand in psoriatic arthropathy. Radiographic and xeroradiographic comparison]. / La mano nell'artropatia psoriasica. Aspetti radiografici e xeroradiografici a confronto.

The hands of 45 cases of psoriasis with arthritis and of 100 cases of rheumatoid arthritis without psoriasis were studied by radiographic and xerographic techniques. The characteristic findings of both methods were recorded separately and compared later. In 44% of cases of psoriatic arthritis, radiographic and xerographic changes are indistinguishable from typical rheumatoid arthritis, but with predominant involvement of distal interphalangeal joints, often bilaterally asymmetric. On the contrary, in 31% of cases, erosive polyarthritis associated with proliferation of subperiosteal new bone (enthesopathy) is present, also with characteristic feature of arthritis mutilans. In 25% of cases, psoriasis of the skin and/or nails is associated with clinical manifestations of rheumatoid arthritis, without roentgenographic findings of arthropathy. The xerographs and radiographs of each patient were compared, assessing the degree of subperiosteal erosion, soft tissue swelling, acro-osteolysis, distruction of small joints and osteolysis of the phalanges, bony ankylosis. The soft tissue swelling ("sausage" finger) was more easily demonstrated by xeroradiography than by conventional radiography, because of its wide recording latitude. However, radiograph remains the technique of choice in the assessment of bone changes of the hand, especially at the first stage of arthritides.

[Radiology of the hand in progressive systemic sclerosis]. / La radiologia della mano in corso di sclerosi sistemica progressiva.

Radiographs and xerographs of the hands of 35 patients with progressive systemic sclerosis (PSS), as defined by the ARA, were reviewed. Patients with "overlap" syndromes (i.e., mixed connective tissue disease, systemic lupus erythematosus or rheumatoid arthritis) have been excluded. Soft tissue changes included atrophy (hide-bound skin), and dystrophic calcifications, particularly in CREST patients (calcinosis, Raynaud phenomenon, esophageal dysmobility, sclerodactily and telangectasia). The most common bony change is resorption of distal phalanges; diffuse osteoporosis is also frequent; the distal interphalangeal and first carpometacarpal joints involvement appear as a distinctive feature of this erosive arthritis.

Heritability and expected selection response for yield traits in blanched asparagus

Despite the continuous breeding that has been conducted with asparagus (Asparagus officinalis L.) since the beginning of the last century, there is little information on parameters for predicting direct and indirect selection response. Yield traits for blanched asparagus production were studied along a two-year period in a half-sib family population planted in Zavalla, Argentina. Half-sib family mean heritability values were low for total yield and marketable spear number (0.31 and 0.35), intermediate for marketable yield and total spear number (0.55 and 0.64), and relatively high for spear diameter and spear weight (0.75 and 0.74). An average increase in marketable yield of 15.9% is expected after each cycle of selection of the top 5% of the families. Total yield failed to express significant genetic correlations with any of the yield components; meanwhile marketable yield showed highly significant relations with market spear number (0.96) and spear weight (0.89). Indirect selection response over yield components (CRx) failed to be advantageous over direct selection (Rx), since the ratio CRx/Rx was always equal or below unity

Estimates of heritability in a blanched asparagus population

To estimate the heritability values of characters frequently used as selective criteria, 32 half-sib families obtained from selected plants of three populations of the asparagus variety Argenteüil were evaluated in a randomized complete block design. The following characters were measured: days to emergence of the first spear, number and diameter of spears, number of stalks, plant height and average weight. The values of realized heritability were estimated and were compared with those obtained by the parent-offspring regression method. Phenotypic correlation coefficients between the different variables were significant. The values of realized heritability for most of the variables were moderate to high (between 0.18 and 0.68), except for days to emergence; lower values were obtained by the regression method. As there was a high degree of heritability, additive genetic factors contributed significantly to the genetic variance, which would allow the selection of phenotypically superior plants for asparagus improvement projects