Field evaluation of an Amaranthus genetic resource collection in China

A total of 229 genotypes of 20 Amaranthus species from the United States Department of Agriculture – Agricultural Research Service (USDA – ARS) National Plant Germplasm Amaranth Collection was evaluated in field experiments in Beijing and Wuhan, China, in 1994. Agronomic traits, including plant height, maturity, leaf number and color, stem color, seed color, branch number, 1000-grain-weight, yield per plant, and resistance to stresses (including diseases) were measured. The results indicated: 1. Many of the species were sensitive to daylength; 2. Cultivated genotypes generally had higher grain yield but were more seriously affected by diseases than non-cultivated species; 3. There was wide diversity in agronomic traits among Amaranthus species and among genotypes within the same species, and several genotypes were identified that appeared to carry favorable agronomic traits of immediate use in cultivar improvement; 4. For introduction of genotypes for use in plant breeding in China, selection should be partially based on matching the climates of the location of origin and the target area for production.     

Amaranthus genetic resources in Indonesia: morphological and protein content assessment in comparison with worldwide amaranths

The morphological variations (growth habit, leaf shape, leaf color, height, stem diameter, number of branches and internodes, leaf area, blade ratio, leaf thickness, number of leaves, and total leaf area) and protein content of 53 Indonesian amaranths (Amaranthus spp.), consisting of weedy-, vegetable-, and ornamental-types, were assessed. The extent of variation in the Indonesian Amaranthus accessions were compared with the worldwide collection (26 accessions from United States Department of Agriculture (USDA) and 5 ornamentals from Nepal) in the experimental field of the University of Tsukuba, Japan. The variation in average values of most morphological traits and protein content in the Indonesian accessions were similar to those of the worldwide germplasm, but the important parameters that influence vegetable yield (e.g., number of leaves and stem diameter) were superior in the Indonesian accessions. Protein content showed a positive correlation with the number of leaves, whereas a negative correlation was observed with leaf thickness. The Indonesian accession of A. viridis and A. dubius showed a great potential to be further selected as parental lines for high protein content and number of leaves. The relatively high protein content of the leaves of Celosia may also potentially serve as an alternative protein source in the tropics.     

Evaluation of Wild Lens Taxa for Agro-Morphological Traits, Fungal Diseases and Moisture Stress in North Western Indian Hills

Exploitation of wild gene pool for breeding is a common practice in an increasing number of cultivated plants. The cultivated lentil could not attain the substantial improvement in the yield potential due to loss of genes for higher productivity and lack of resistance against biotic and abiotic stresses. The absence of evaluation data of wild lentils for characters of economic importance, besides biotic and abiotic stresses, is one of the constraints in their use in lentil breeding programme. In the present study, 70 wild accessions from four wild Lens subsp./sp. (L. culinaris subsp. orientalis, L. odomensis, L. ervoides and L. nigricans) along with 3 checks (Precoz, PL-406 and PL-639) were evaluated for phenological and agro-morphological characters, for their reaction to three fungal diseases (wilt, powdery mildew and rust) and screened for tolerance to moisture stress. The wild accessions showed higher performance for branches/plant as compared to cultivated genotypes. Similarly, a few accessions of L. culinaris subsp. orientalis were earlier to flower and had higher seeds and seed yield/plant as compared to cultivated lentil. However, some were comparable with cultivated genotypes for flowers/peduncle, peduncle length and plant height. The mean performance for flowers per peduncle, leaflets per leaf, plant height, seeds and seed yield per plant increased, while decreased for days to flowering and maturity, and branches per plant during the evolution of cultivated lentil from the wild Lens taxa. Of Lens taxa, L. nigricans had the maximum resistant accessions for biotic and tolerance to abiotic stresses. The valuable variation existing among wild accessions can be exploited following introgression with cultivated lentils. It will help in the flow of useful genes from wild to cultivated lentil for generating wide spectrum of variability and its subsequent use in genetic restructuring of lentil.     

Switchgrass (Panicum virgatum L.) from North Dakota—a New Bioenergy Crop for the Nemoral Zone of Europe

ABSTRACT

Parallel to the growing interest in switchgrass (Panicum virgatum L.) in southern countries of Europe, there is enhanced interest in knowing about its potential adaptability in the European regions with cool and moderate climates. The objective of this work was to characterize important agricultural parameters of switchgrass originated from North Dakota in order to identify the most valuable accessions for further research, propagation, and breeding in the Nemoral zone of Europe. The selection aimed at evaluating overwintering and productivity of switchgrass, with the ultimate objective of biomass quality improvement. Field trials were carried out in the central lowland of Lithuania during 2012–2014 on 33 germplasm accessions of switchgrass originating from North Dakota. Allthe tested accessions exhibited almost similar overwinter survival rate, i.e., 93.7–96.7%. Significant differences were observed in mean dry matter yields of all the tested accessions harvested once or twice per season (P < 0.05). The higher yielding accessions during both study years were differentiated. The yield potential of these accessions depended on a number of morphological traits, including internode thickness, plant height, panicle length, and leaf and stem weight per tiller (P < 0.05). Ash and mineral composition was associated with the genotype and the year of biomass harvest (P < 0.05). The switchgrass genotypes originating from North Dakota appeared to be adaptable to the European environment with cool and moderate climate and short growing season. The best-performing accessions can serve as a valuable genetic source for future breeding programmes.     

Phenotypic and genomic characterization of vine cactus collection (Cactaceae)

Hylocereus (Berger) Britton et Rose, Selenicereus (Berger) Britton et Rose and Epiphyllum Haw. species have commercial potential as exotic fruit crops in semi-arid and arid lands. The high genetic variability among these species offers an opportunity for commercial cultivation. Toward this end we investigated genomic and morphological characteristics including: nuclear DNA content (2C-values), stomatal length and density, potential yield and reproductive parameters in 64 Hylocereus, Selenicereus and Epiphyllum accessions. Nuclear DNA content ranged from 3.21 pg for S. grandiflorus (L.) Britton et Rose spp. grandiflorus to 8.77 pg for H. megalanthus (Vaup.) Bauer. All species were diploid except the tetraploids H. megalanthus and S. vagans (Bgek.) Britton et Rose. Stomatal length and density, fruit weight, potential yields, number of viable seeds per fruit and fruit maturation times were highly variable among accessions. No significant correlations were found between stomatal length, density, and nuclear DNA content, nor between fruit weight and seed number. The high genetic variability found between the accessions here provides further support for the excellent prospects of conserving and domesticating these exotic species.     

Systematics and taxonomic delimitation of vegetable,grain and weed amaranths: a morphological and biochemical approach

Amaranthus is a cosmopolitan genus comprising large number of species with many morphotypes cultivars/accessions having diversified morphological features. The species, morphotypes within Amaranthus are very closely related requiring microclassification even revision in present taxonomic status. Most of the works have been done employing grain Amaranthus and their putative ancestors applying morphological and molecular data. In present study along with morphological features, phenolic compounds (secondary metabolites), isozyme profile of acid phosphatase were applied to get comprehensive reflection of interrelationship and relative closeness among the species, morphotypes/accessions of few vegetable, grain and weed Amaranthus. Both the vegetable and grain Amaranthus are supposed to have originated from respective weed progenitor through occasional outcrossing and gradual domestication. The study strongly vouched the previous interpretations regarding interrelationship of grain Amaranthus and their derivation from their putative progenitor also showed clear separate clustering of vegetable and grain Amaranthus with their close relatives. A sharp congruence in cluster pattern was achieved between morphological dendrogram and cumulative dendrogram computed on morphological and biochemical parameters, which is a rare event in systematics.     

Characterisation of agro-morphological traits of corchorus accessions

The genus Corchorus includes nutrient-rich indigenous leafy vegetables often grown or harvested in the wild in Africa. It has potential to contribute to food security, but there is need to improve it as a crop through plant breeding. However, not much is known about the genetic variability among Corchorus species. The aim of this study was thus to characterise the available germplasm of Corchorus accessions and investigate heritability of their agro-morphological traits. Eleven Corchorus accessions (4 South African and 7 from the World Vegetable Center) were evaluated in a field study at Roodeplaat, South Africa, for their morpho-agronomic traits using a randomised complete block design with three replications across two seasons (2015/2016 and 2016/2017). Data were subjected to ANOVA, principal component analysis and cluster analysis. Broad sense heritability, genetic advance, genetic parameters and correlations were determined among the accessions and traits. The Corchorus accessions showed significant (P < .05) differences in all the quantitative traits evaluated. The data showed significant variability among the studied Corchorus accessions in their agro-morphological traits for exploitation in future breeding programmes that in turn can contribute to the improvement of this crop.     

Genetic variation among populations of wild safflower, <Emphasis Type="Italic">Carthamus oxyacanthus</Emphasis> analyzed by agro-morphological traits and ISSR markers

Wild species of safflower, Carthamus oxyacanthus Bieb., is highly crossable with cultivated species, C. tinctorius L. and could be directly exploited in broadening safflower gene pool and improving the crop for biotic and abiotic stress environments. In this study, genetic diversity among accessions of C. oxyacanthus and their relationships with cultivated safflower were evaluated using agro-morphological traits and polymorphic inter-simple sequence repeats (ISSR) markers. Significant variation was observed among accessions particularly for seeds per capitulum, seed yield per plant, harvest index and capitula per plant. Cluster analysis based on agro-morphological traits classified the wild accessions in two groups according to their geographical regions, and separated them from the cultivated genotypes. ISSR marker also revealed a high genetic variation among the accessions, and cluster analysis based on this marker divided genotypes into four groups, with cultivated ones in a separate clade. Genetic variation observed among the wild safflower germplasm at the DNA level was higher than the agro-morphological traits, indicating that ISSR is an effective marker system for detecting diversity among safflower genotypes and their genetic relationships. Accessions of C. oxyacanthus with high genetic relationship to cultivated species could be used for interspecific hybridization in breeding programs of safflower.     

Diversity in White Lupin (<Emphasis Type="Italic">Lupinus albus</Emphasis> L.) Landraces from Northwest Iberianplateau

All the accessions (35) of white lupin (Lupinus albus L.) landraces collected from northwest Iberian plateau and maintained at the Spanish germplasm collection (CRF of INIA), were studied with the general objective of assessing the biodiversity of these landraces and to ascertain their value as genetic resources for the development of germplasm adapted to the areas where they were collected with long and chilly winters. The characterization study comprised 51 qualitative and 50 quantitative characters. Quantitative parameters were analyzed by Principal Components Analysis (PCA). The 2-dimensional plot (49.3% of cumulative variability) formed a main group of accessions and 4 outliers (#1, #9, #27 and #28) separated in the first PC. The characters with a higher contribution to the first PC were inflorescence length, leaf petiole length and leaf central foliole area. The presence of alkaloids, the percentage of plants killed by soil borne fungal diseases, the phenology, the yield per plant and yield components were also assessed. Twenty six accessions (the main group in the PCA plot) showed high homogeneity, with the following highlights: bitterness, indeterminate growth habit, early ripeness and spring sowing with the exception of #18, in which seeding date is unknown and it had a later phenology. By contrast accessions #9 and #27 were bitter of autumn sowing with determinate growing habit and they had the longest values of primary inflorescence length and a later phenology when they were sown in spring. Average values for yield and yield components showed a broad range of variation between accessions. The main yield component was the number of pods per plant. Accession #22 had the highest mean seed mass, although this had not significant influence in yield. Accession #17 showed the highest yield and #1 the lowest. This last also had the lowest values of inflorescence length, leaf petiole length and leaf central foliole area. No significant differences of resistance to soil-borne fungi were found between accessions. The year had a significant effect in the phenology, yield and yield components except for number of seeds per pod. The studied material might be of interest for the development of spring sowing germplasm adapted to north Iberian peninsula.     

Genotypic diversity and patterns of variation in a germplasm material of Ethiopian mustard (Brassica carinata A. Braun)

The amphidiploid species Brassica carinata A. Braun is believed to have originated in the plateaus of Ethiopia and has been cultivated there as an oilseed crop since antiquity. The species possesses agronomically important genes of rare occurrence. Although there is a large number of collections in Ethiopia, information on the extent of their genetic diversity is very limited. Thirty-six accessions of ecologically diverse regions were tested at three locations and multivariate analyses on 13 morphological and seed characters were performed. There was generally a large amount of divergence in all characters. Geographic isolation of genes, however, was not observed. Both principal component and cluster analyses disclosed complex relationships among the accessions and characters. Accessions with potential genes of interest to improve earliness, yield components and oil and protein contents have been identified. Length of growing period and yield components contributed most for divergence and clustering pattern. Oil, glucosinolate and protein contents also varied among the accessions but not so much between clusters. Increasing protein in high-glucosinolate genotypes reduced oil content and should be more efficient in genotypes of low-glucosinolate genetic background.     

Variations in morphological and agronomic traits among Jerusalem artichoke (Helianthus tuberosus L.) accessions

Jerusalem artichoke is a diversely-utilized crop. Selection for high yield, inulin content and other economically important traits are useful for improving this crop. The objectives of the present study were to evaluate genetic variability for qualitative and quantitative traits among Jerusalem artichoke accessions and to identify different groups of accessions using morphological and agronomic traits. Seventy-nine accessions were evaluated in a randomized complete block design with two replications in the late rainy season 2008, the early rainy season 2009 and the late rainy season 2009 at Khon Kaen University agronomy farm, Thailand. Morphological and agronomic characteristics were evaluated for genetic variations. High variations were found among Jerusalem artichoke accessions for qualitative and quantitative characters, and selection for these characters is possible. High variations were observed for tuber width, number of tubers/plant, biomass, fresh tuber yield and tuber size. Correlation coefficient between fresh tuber yield and tuber size was positive and significant (0.58, P ≤ 0.01). Improvement of tuber size is a means to improve yield and tuber quality. Based on morphological and agronomic characteristics, Jerusalem artichoke accessions were clustered into four distinct groups (R² = 0.88). These groups may be used as parental material to generate progenies for further improvement of this crop. This information will enable breeders to make informed decisions about possible heterotic groups for their breeding programs and germplasm conservation.     

Germplasm characterization of Sesbania accessions based on multivariate analyses

Nineteen Sesbania accessions were investigated, in a total of six species, to characterize the accessions based on morphological and agronomic data using multivariate methods, to identify a core set of morphological and agronomic attributes to be used in germplasm characterization of Sesbania spp., and to evaluate the forage potential of these accessions. Plots, in randomized block design, consisted of single 16 m-long rows of eight plants, spaced at 2 m between plants and 3 m between rows. Morphological data were obtained from the first four plants in each plot. The four remaining plants, submitted to four cuts at a height of 1 m, provided agronomic data. Principal component analysis indicated that variance accumulated by the first two components for morphological and agronomic data was 74.4% and 77.0%, respectively. Two large groups of accessions were formed in the cluster analysis for morphological data, one consisting of S. virgata, subgenus Daubentonia and the second group comprising the other five species. Cluster analysis using agronomic data classified higher yielding perennial species in three groups, and the annual species, which stood out principally in relation to seed production, in three other groups. Accession n° 8 of S. sesbanwas classified in an isolated group due to its forage superiority. A character discard resulted in the selection of eight characters: floral initiation, pod and leaf length, number of leaflet pairs, plant regrowth height, leaf dry matter yield, seed production and vigour, indicated as a core set of attributes for Sesbania germplasm characterization.     

Genetic diversity of some accessions of Cucurbita maxima from Spain using RAPD and SBAP markers

Increasing the knowledge of the molecular diversity of a crop is essential for extending its genetic base, identifying cultivars and selecting parental varieties for breeding programs. In this sense, Cucurbita maxima Duch. is poorly characterised. Nineteen accessions of this species and 8 related Cucurbita accessions were included in a genetic diversity analysis. For this purpose, Random Amplified Polymorphic DNA markers (RAPDs), which analyse neutral variability, and Sequence-Based Amplified Polymorphism (SBAPs), which preferentially amplify coding regions of the genome, were used. While the UPGMA cluster and the principal coordinates analysis obtained using RAPDs did not group the different accessions according either to fruit morphological criteria or to passport data (origin and agro-climatic conditions), the principal coordinates analysis obtained using SBAPs grouped the different pumpkin accessions fundamentally according to the type of use (human consumption, animal fodder or ornamental). This passport trait is reported to be associated with agronomic breeding characters of interest. The usefulness of both types of markers for discriminating accessions of breeding interest is discussed.     

Evaluation of phenotypic variation in a worldwide germplasm collection of safflower (<Emphasis Type="Italic">Carthamus tinctorius</Emphasis> L.) grown under organic farming conditions in Germany

An investigation was conducted to determine the extent of diversity and relationships among a worldwide safflower (Carthamus tinctorius L.) germplasm collection and to find out adapted accessions that can be used in an organic safflower breeding program in Germany. A total of 468 accessions was studied under organic farming conditions at Kleinhohenheim experimental station during the seasons of 2004 and 2005. All the accessions were evaluated for 12 phenotypic traits and three rated diseases. Multivariate analyses have been used to measure the diversity in a subset of 200 accessions and 11 geographical regions. Generally, the study showed that there was a large genetic variation within accessions. A coefficient of variation (CV%) for investigated traits and diseases ranged from 2.9 to 91.0% with the highest CV was recorded for yield/m2, yield/plant and seeds/plant. The most accessions that originated in Europe revealed relatively better performance compared to non-Europeans. High yielding, early maturing, and disease tolerant accessions were identified. However, the low oil content (8.7–22.8%) is the primary concern in this germplasm collection. The degree of heritability varied between 10% for lodging to 86% for plant height. Genotypic coefficient of correlation (r _g) was slightly higher for many traits than the respective phenotypic coefficient. Oil content and seed yield/m2 were highly significantly correlated (r _g = 0.78). The genotypic coefficient of correlation showed that selection for seeds/plant and thousand kernel weight was effective for improvement of seed yield and oil content. The results of the principal component analysis and the clustering pattern of accessions were consistent with the results of analysis of variance. About 78% of the total phenotypic diversity in the germplasm was explained on the basis of four principal components and 88% of the total variation among geographical regions was contributed by the first three principal components. The distribution of the accessions within clusters has no apparent relationship with the geographical origin. However, many of the European accessions have a tendency to stay together.     

Evaluation of Introduced and Naturalised Populations of Red Clover(<Emphasis Type="Italic">Trifolium pratense</Emphasis> L.) at Pergamino EEA-INTA,Argentina

Red clover (Trifolium pratense L.) is a temperate forage species that is extensively used in Argentina, but little effort in breeding has been made so far. Meanwhile, red clover breeding is strong in Europe and North America. In order to contribute to the utilisation of red clover genetic resources, 39 accessions of different origins were evaluated at Pergamino Inta Experimental Station. A broad phenotypic variation was detected for many of the 14 attributes considered. Variables that discriminate populations are related to seed production and winter yield. Two different groups clustered according to morphologic and productive mean attributes, and these groups were related to geographic origin of accessions.     

Molecular characterization of mulberry genetic resources indigenous to India

Mulberry (Morus L.) is essential for the sericulture industry as the primary feed for the silkworm Bombyx mori L. in India, with its long tradition of practicing sericulture, has a large number of indigenous cultivars. Since knowledge on the genetic divergence of these cultivars/varieties is essential for proper conservation and utilization, Inter Simple Sequence Repeat (ISSR) profiling was employed to assess genetic relationships among 34 mulberry accessions, collected from different regions of India. By using 12 ISSR primers, which produced 72 markers displaying a high degree of polymorphism (94.4%), genetic dissimilarity coefficients were calculated for each pair of the accessions and clustering of the accessions with Unweighted Pair Group Method using Arithmetic average (UPGMA) analysis was done to unravel the genetic diversity among the accessions. The dissimilarity coefficients varied from 0.111 to 0.692. UPGMA analysis generated a dendrogram with six groups and five isolates. Clustering of the accessions did not correspond with the information on the geographic origin of many of the accessions. Two-dimensional representations of the relative positions of the accessions with regards to divergence using the first two canonical variates as co-ordinate axes revealed considerable variability among the cases in each group. Further, Discriminant Function Analysis (DFA) showed changes in the geographic origin of 11 accessions and species status of 20 accessions.     

Chromatographic fingerprinting of <Emphasis Type="Italic">Lupinus luteus</Emphasis> L. (Leguminosae) main secondary metabolites: a case of domestication affecting crop variability

Secondary metabolites (SMs), such as alkaloids and raffinose oligosaccharides (RFOs), play important roles in plant physiology. Although alkaloid and RFO phenotypic variation has been reported for yellow lupin (Lupinus luteus L.), most evaluations have used a reduced number of accessions; thus, limiting the understanding of accumulation patterns and variation ranges. The main goal of this research was to assess alkaloid and RFO content in a diverse L. luteus sample to understand possible SM accumulation patterns across this legume species. Eighteen yellow lupin accessions were analyzed using high performance thin layer chromatography to provide insights on seed and leaf RFO and alkaloid phenotypic variation. Co-dominant markers (170) were used to examine genetic relationships among L. luteus accessions and possible accumulation patterns across closely related genotypes. Significant differences were observed for seed and leaf RFOs. Total seed RFO accumulation ranged from 79.738 to 131.079 mg g^?1. Raffinose, stachyose, and verbascose were observed in all genotypes’ seeds, but at different RFO concentrations. Raffinose was the only RFO detected in leaves (2.793–0.4224 mg g^?1). Total alkaloid accumulation ranged from 0.22 to 15.12 and 0.00 to 8.007 mg g^?1 for seeds and leaves, respectively. Lupinine, sparteine, and gramine were observed in seeds and leaves, and showed a wide range of variation. Neighbor-Joining (NJ) analysis showed an apparent pattern of seed alkaloid accumulation, most likely due to domestication events. However, high RFO accumulating accessions were scattered across the NJ tree. Alkaloid and RFO significant phenotypic variation will not only help to understand the roles of these SMs in L. luteus, but also to uncover the genetic basis behind their accumulation.     

Biomass production and related characters in the core collection of Pisum germplasm

Retention of residue on the soil surface following harvest is an effective method of reducing soil erosion from both wind and water. The pea crop produces small amounts of residue to effectively reduce soil erosion. Severe erosion occurs in pea production areas such as the Palouse Region of the US Pacific Northwest (PNW) when low residue crops such as spring pea or lentil are followed by fall-sown wheat. The current study was conducted to determine the range of total aboveground biomass (TAB), seed yield, and straw (residue) production from the plant identification (PI) accessions that comprise the core collection of Pisum germplasm. In addition, the potential for increasing seed yield and straw production simultaneously was evaluated. Three hundred and ninety PI accessions were screened in the field in 1996 and 1997. The variation for TAB, seed yield and straw production among the PI accessions exceeded that of the controls both years. Seed yield was positively correlated with straw production (r = 0.81, p< 0.01) indicating that seed and straw production can be increased simultaneously through positive selection for both traits. Significant favorable variation is present among accessions in the USDA core collection of Pisum germplasm which could be used to increase both seed yield and total biomass production of adapted breeding lines.