Genetic,phenotypic, and environmental correlations in black medic,Medicago lupulina L., grown in three different environments

We have investigated the relationship between phenotypic and genetic correlations among a large number of quantitative traits (36) in three different environments in order to determine their degree of disparity and whether phenotypic correlations could be substituted for their genetic counterparts whatever the environment. We also studied the influence of the environment on genetic and phenotypic correlations. Twenty accessions (full-sib families) ofMedicago luPulina were grown in three environments. In two of these two levels of environmental stress were generated by harvesting plants at flowering and by growing plants in competition with barley, respectively. A third environment, with no treatment, was used as a control with no stress. Average values of pod and shoot weight indicate that competition induces the highest level of stress. The genetic and phenotypic correlations among the 36 traits were compared. Significant phenotypic correlations were obtained easily, while there was no genetic variation for 1 or the 2 characters being correlated. The large positive correlation between the genetic and phenotypic correlation matrices indicated a good proportionality between genetic and phenotypic correlations matrices but not their similarity. In a given environment, when only those traits with a significant genetic variance were taken into account, there were still differences between genetic and phenotypic correlations, even when levels of significance for phenotypic correlations were lowered. Consequently, it is dangerous to substitute phenotypic correlations for genetic correlations. The number of traits that showed genetic variability increased with increasing environmental stress, consequently the number of significant genetic correlations also increased with increasing environmental stress. In contrast, the number of significant phenotypic correlations was not influnced by the environment. The structures of both phenotypic and genetic matrices, however, depended on the environment, and not in the same way for both matrices.     

Polytene chromosomes in cultured pea roots (Pisum,Fabaceae)

The experiments on cultured pea roots (Pisum sativum cv. Alaska and Dwarf Telephone) are summarized in Table 1. Nuclear growth and mitosis occurred mainly in cultures in which the medium of Torrey and Shigemura was supplemented with 6 p.p.m. 2,4-D and 1 p.p.m. kinetin. The greatest reaction was observed in 16-day cultures of cv. Alaska. Nuclei had increased in size, and prophases diploid and polyploid, with normal chromosomes, diplochromosomes or larger bundles of chromatids were visible. Metaphases which ranged from 2 n to an estimated 32 n had normal chromosomes with two chromatids. Polytene chromosomes, in diploid, rarely in tetraploid number, occurred in numerous cortex cells. They did not show banding, and their telomeres, spread into individual chromatids, were attached to the nuclear membrane. In some cells the polytene chromosomes were condensed into spherical structures, obviously a stage in their falling apart; the last stage of this process is a polyploid metaphase.     

Variability in nuclear DNA content within pigeonpea,Cajanus cajan (Fabaceae)

4C DNA values have been estimated in 16 cultivars ofCajanus cajan by cytophotometry. The values range between 6.19 pg to 7.97 pg, a 23.6% variation. The cultivars form four groups which differ significantly from each other but have insignificant difference within them. The implications of this variability with respect to the heterogeneity and origin of this legume crop are discussed.     

Variation at isozyme loci in wildVigna unguiculata (Fabaceae,Phaseoleae)

An electrophoretic comparison of variation at 37 presumptive isozyme gene loci was performed for 55 wildVigna unguiculata accessions. The analysis included seven subspecies, covering the whole range of variation available in wildVigna unguiculata. The results of the isoenzymatic study broadly confirmed the previous infraspecific classification inferred from morphological data. Although the southern taxa (e.g., subsp.tenuis, subsp.stenophylla) are as yet too poorly sampled to discuss in depth, wildVigna unguiculata can be divided into one mainly autogamous annual group (including subsp.pubescens and var.spontanea) and several widely divergent perennial subspecies.     

Isozyme variation and alleged progenitor-derivative relationships in theMedicago murex complex (Fabaceae)

Chromosomal studies ofMedicago lesinsii (n = 8) and its close relativeM. murex (n = 7) have led to the competing hypotheses that the latter is derived directly from the former, or that both originated from a common ancestor. In contrast to the relatively variableM. murex, M. lesinsii proved to be almost uniform isozymically, except that most populations of Greece differed by one allele from plants of the remainder of the range. This Greek variant ofM. lesinsii was indistinguishable from one of the isozyme variants ofM. murex. The greater level of allozyme variation inM. murex was consistent with its greater ecological amplitude and competitive ability. Also, this suggests thatM. murex is unlikely to have originated directly from the less variableM. lesinsii. The data suggest that either both species originated from a common ancestor, or that the n = 8 species evolved from the n = 7 species, a mode of chromosome evolution not previously hypothesized for the genus.     

Isozyme polymorphism in some yellow- and blue-floweredVigna species complexes (Fabaceae, Phaseoleae)

An electrophoretic comparison of variation at 28 isozyme loci was performed for 58Vigna accessions belonging to theV. luteola, V. ambacensis, andV. racemosa groups of species. In all three groups, strong divergence is noted between results and actual nomenclature.     

Seed flavonoids of thePodalyrieae andLiparieae (Fabaceae)

A study of the phenolic compounds of the closely related papilionoid tribes,Podalyrieae andLiparieae, proved that the flavonoid patterns of hydrolysed seed extracts are remarkably conservative. Butin (7, 3, 4-trihydroxyflavanone), 3-hydroxydaidzein (7, 3, 4-trihydroxyisoflavone), vicenin-2 (6, 8-di--D-glucopyranosyl-5, 7, 4-trihydroxyflavone) and orobol (5, 7, 3, 4-tetrahydroxyisoflavone) were isolated and identified as the major flavonoids. The seeds ofAmphithalea, Coelidium, Liparia, Xiphotheca, Calpurnia, Stirtonanthus andPodalyria accumulated three isoflavone O-glycosides that yielded 3-hydroxydaidzein on hydrolysis. In contrast,Virgilia contained a unique combination of vicenin-2 and orobol. Vicenin-2 was also present inCalpurnia as a major compound, butStirtonanthus insignis was the only other species studied that contained orobol (in trace amounts only). Butein, a chalcone, was reported byHarborne from the seed ofCyclopia subternata. This compound's flavanone analog, butin, was the principal component inCyclopia. A cladistic analysis, using flavonoid, alkaloid and morphological data, showed that the seed flavonoids of thePodalyrieae andLiparieae behave rather poorly as cladistic characters. They are, however, of considerable taxonomic value at the tribal level favouring the opinion that the two tribes should be combined. The apparent absence of flavonoids in the seed ofHypocalyptus supports the suggestion that it should be excluded from theLiparieae. Flavonoids also show that theArgyrolobium-group is very different from the tribeCrotalarieae and support the recent transfer of this group to the tribeGenisteae.     

Zur Bewertung der Blattdornen vonHalimodendron halodendron (Fabaceae)

Halimodendron halodendron is a spiny shrub of north-western Asia. The spines are formed by the rachises of the paripinnate leaves. After abscission of pinnae the rigid rachises remain for several years. In culture these rachis spines do not develop fully.

Herrn Univ.-Prof. Dr.Walter Leinfellner zum 70. Geburtstag gewidmet.     

A newAstragalus (Fabaceae) from southern Peloponnisos

Astragalus maniaticus (Fabaceae), a new species endemic to the Mani Peninsula in Peloponnisos, southern Greece, is described and illustrated. Its closest affinities are still uncertain but within Greece, it lacks close allies.Dedicated to emer. Univ.-Prof. DrFriedrich Ehrendorfer on the occasion of his 70th birthday     

Diversity of seed storage protein patterns in wild peanut (Arachis,Fabaceae) species

55 accessions of wild peanuts (Arachis spp.) introduced from South America were analyzed for seed storage protein composition using SDS-PAGE electrophoresis. The objectives of the study were to evaluate variability within sect.Arachis and to classify taxa based on protein composition. 25 different band positions were resolved. Individual accessions had 11 to 18 bands which included the conarachin region (MW > 50 kD), two to five bands in the acidic arachin region (MW 38–49.9 kD), three to seven in the intermediate MW region (23 to 37.9 kD), two to five bands in the basic arachin region (18–22.9 kD), and one to three bands in the low MW protein region (14–17.9 kD). These data were utilized in a principal coordinate analysis based on the matrix of genetic distances between all pairs of the 55 accessions. Several groups of accessions conformed to expected species classification includingA. batizocoi, A. stenosperma, andA. monticola; whileA. duranensis, A. cardenasii, A. helodes, andA. correntina did not form good groups. The study showed that great diversity exists for protein profiles and seed storage proteins have potential for aiding species classification and for serving as markers for interspecific hybridization studies.     

Seed protein polymorphism inVicia sativa agg. (Fabaceae)

TheVicia sativa aggregate contains plants with different chromosome numbers karyotypes; they are still cross-compatible and have partially fertile F₁-hybrids. There is also wide adaptive radiation and geographic distribution. The seed protein profiles ofV. sativa agg. are remarkably variable but no band or bands could be related to a specific karyotype, chromosome number or taxon, and variation within and between karyotypes are of the same magnitude. It is suggested that variation in the seed proteins ofV. sativa agg. might be an important agent for acquiring ecological flexibility, and that it is probably enhanced by interkaryotypic hybridization.     

Chromosome polymorphism,hybridization and colonization in theVicia sativa group(Fabaceae)

Vicia sativa L. s. l. is presented as a variable complex consisting of 7 subspecies, including wild types, weedy races and cultivated derivatives. The group is characterized by: (a) Decreasing aneuploid (dysploid) chromosome series (2n = 14 12 10,); (b) wide variation in karyotypes; (c) pronounced weediness and colonization of disturbed habitats; (d) cohabitation of several forms; (e) intergradations between the main morphological types; (f) predominance of self-pollination; (g) lack of full sterility between the main chromosome types. Plants with different chromosome numbers or different karyotypes are loosely interconnected by occasional hybridization, particularly in disturbed habitats. Colonization appears to be associated with reticulate evolution and the recombination of previously separated gene pools. The wide karyotypic polymorphism characteristic for this complex is interpreted as a result of such relatively recent processes.     

Morphological and microsatellite diversity associated with ecological factors in natural populations of Medicago laciniata Mill. (Fabaceae)

Genetic variability in 10 natural Tunisian populations of Medicago laciniata were analysed using 19 quantitative traits and 12 polymorphic microsatellite loci. A large degree of genetic variability within-populations and among-populations was detected for both quantitative characters and molecular markers. High genetic differentiation among populations for quantitative traits was seen, with Q _ST = 0.47, and F _ST = 0.47 for microsatellite markers. Several quantitative traits displayed no statistical difference in the levels of Q _ST and F _ST . Further, significant correlations between quantitative traits and eco-geographical factors suggest that divergence in the traits among populations may track environmental differences. There was no significant correlation between genetic variability at quantitative traits and microsatellite markers within populations. The site-of-origin of eco-geographical factors explain between 18.13% and 23.40% of genetic variance among populations at quantitative traits and microsatellite markers, respectively. The environmental factors that most influence variation in measured traits among populations are assimilated phosphorus (P₂0₅) and mean annual rainfall, followed by climate and soil texture, altitude and organic matter. Significant associations between eco-geographical factors and gene diversity, H _e , were established in five-microsatellite loci suggesting that these simple sequence repeats (SSRs) are not necessarily biologically neutral.     

Karyotype and C-banding inTrigonella sectionFoenumgraecum (Fabaceae)

The six species of the sectionFoenum-graecum ofTrigonella have the same chromosome number, 2n = 16.T. gladiata andT. cariensis have fairly symmetrical karyotypes, while those ofT. foenum-graecum, T. berythea, T. macrorrhyncha andT. cassia are asymmetrical. C-bands are present in all six species but the number of bands and their positive vary considerably among the species. The karyotype evidence suggests that none of the available species of theFoenum-graecum section can be considered as the wild progenitor of fenugreek.     

Sero-systematics ofCytisus sect.Trianthocytisus (Fabaceae)

The serological reaction of seed proteins provides evidence for a partly new systematic arrangement ofCytisus sect.Trianthocytisus and ofCytisus s.l. Proposed modifications agree with recent advances in morphological taxonomy. Sect.Trianthocytisus includes only two species,C. villosus andC. aeolicus. Its position is central within the genus, and this fact agrees with the proposed retypification ofCytisus (type species:C. villosus).C. emeriflorus, formerly included in the same section, constitutes the monospecific sect.Emeroides, which is intermediate towards the genusLembotropis. This is serologically isolated and includes onlyL. nigricans. It is confirmed thatC. sessilifolius should be removed from the genusCytisus as a monospecific genus:Cytisophyllum Lang which is closely allied toHesperolaburnum and toPodocytisus, the most primitive genera ofGenisteae.     

Sex allocation and mating systems in pigeonpea,Cajanus cajan (Fabaceae)

Sex allocation theory predicts that: (1) resources allocated to androecium should decrease with an increase in selfing, (2) a decrease in androecium biomass should be accompanied by an increase in the biomass of pistils, and (3) a decrease in androecium biomass should be coupled with a decrease in flower size, specifically corolla biomass. Another predicted change in reproductive traits associated with variation in selfing concerns seed to ovule ratios, but does not directly stem from sex allocation theory. It has been postulated that seed to ovule ratios should be positively correlated with the amount of selfing. These predictions were tested for six accessions of pigeonpea,Cajanus cajan L., that differed in selfing rates. The results were remarkably in accordance with the predictions. We conclude that sex allocation theory provides a powerful tool to understand the evolution of many reproductive traits in plants.     

Fruit dimorphism inPhaseolus sublobatus (Fabaceae) and its evolutionary significance

Populations of the annualPhaseolus sublobatus from different ecogeographical zones are genetically differentiated. In twelve populations from the western ghats (Maharashtra range) chasmogamous flowers are arranged in peduncled capitate racemes borne in leaf axils of higher nodes. One population (Poona Race S₄) has additional inflorescences, also with chasmogamous flowers, on the main axis between the cotyledonary node and the ground. When the pods of these flowers ripen, the inflorescence gradually coils and, eventually, gets bury the fruits in the soil. This phenomenon is not known in any other plant.—The seed-coat patterns as revealed by SEM, and germination behaviour of both aerial and subterranean seeds are similar, and both types of seeds lack dormancy.—Heavy seed predation selection pressure is probably the principal cause for the evolution of fruit dimorphism inP. sublobatus. The origin of geocarpy in relation to fruit dimorphism and seed predation is discussed.     

Isoenzyme variation in the wild relatives ofVicia faba (Fabaceae)

Electrophoretic analysis of five enzyme systems, LAP, PGI, SKDH, SOD and 6-PGDH, among 102Vicia accessions representingV. bithynica and seven species of theV. narbonensis complex, namelyV. eristalioides, V. kalakhensis, V. johannis, V. galilaea, V. serratifolia, V. narbonensis andV. hyaeniscyamus, has been performed. The recorded variation was tentatively assigned to 41 allelic genes at eight loci; intraspecific variation was observed in all species except forV. eristalioides. The results obtained were compared with the corresponding data reported earlier forV. faba. Hierarchical grouping of the investigated taxa, includingV. faba, was based onNei's genetic identities calculated from the allozyme frequency data.Vicia faba andV. bithynica were shown to be most distantly related to one another and to the remaining species investigated.Vicia serratifolia appeared to be a peripheral member of theV. narbonensis complex. The results are discussed with reference to genetic diversity and taxonomic relationships of the species under study.     

An analysis of the B genome speciesArachis batizocoi (Fabaceae)

Arachis batizocoi Krap. & Greg. is a suggested B genome donor to the cultivated peanut,A. hypogaea L. Until recently, only one accession of this species was available in U.S.A. germplasm collections for analyses and species variability had not been documented. The objective of this study was to determine the intraspecific variability ofA. batizocoi to better understand phylogenetic relationships in sect.Arachis. Five accessions of the species were used for morphological and cytological studies and then F₁ intraspecific hybrids analyzed. Some variation was observed among accessions—for example, differences in seed size, plant height and branch length. The somatic chromosomes of accessions 9484, 30079, and 30082 were nearly identical, whereas, the karyotypes of accessions 30081 and 30097 have several distinct differences. For example, 30081 had significantly more asymmetrical chromosomes 2 and 6 and more median chromosomes 7 and 10, and 30097 had significantly more asymmetrical chromosomes 3 and 10 and more median chromosomes 1 and 5 than accessions 9484, 30079, and 30082. All F₁ hybrids among accessions were highly fertile. Meiotic observations indicated that hybrids among accessions 9484, 30079, or 30082 had mostly bivalents. However, quadrivalents were observed when either 30081 or 30097 was crossed with the above three accessions and 30081 × 30097 had quadrivalents, hexavalents and octavalents. The presence of translocations is the most likely cause of multivalent formation inA. batizocoi hybrids. Cytological evolution via translocations has apparently been an important mechanism for differentiation in the species.Paper No. 12382 of the Journal Series of the North Carolina Agricultural Research Service, Raleigh, NC 27695-7643.     

Seed protein electrophoresis in sectionFoenum-graecum ofTrigonella (Fabaceae)

The seed proteins ofTrigonella foenum-graecum, T. berythaea, T. macrorrhyncha andT. gladiata were fractionated on polyacrylamide gels in anodic and cathodic systems. Similarity indices between the profiles of any two species indicated close affinity betweenT. gladiata andT. macrorrhyncha and betweenT. foenum-graecum andT. berythaea. It has been pointed out that according to morphological resemblance and similarity index of the seed protein profileT. berythaea is closer to the cultigen than any other species of sectionFoenum-graecum, but these two species are strongly isolated from one another by the albino seedlings of their F₁ hybrids.