Combining ability and inheritance of pod and cluster number inPhaseolus mungo L.

Summary A set of sixPhaseolus mungo lines was studied in a diallel cross over two generations to investigate general and specific combining ability and mode of inheritance for cluster and pod number. General combining ability effects were more important for both characters.Per se performance appeared to be a good index to rank the parental lines for general combining ability. Additive gene effects with partial dominance to overdominance for these traits were noted. High cluster and pod number seem to be governed by recessive genes.

---

Zusammenfassung Für zwei Ertragskomponenten beiPhaseolus mungo, die Zahl der Fruchtstände und der Hülsen je Pflanze, wurde die allgemeine und spezifische Kombinationseignung sowie ihre Vererbung untersucht. Die Prüfung erfolgte über zwei Generationen an Diallel-Kreuzungen von 6Phaseolus-Linien.Für beide Merkmale war die allgemeine Kombinationseignung von größerer Bedeutung. Die Leistungen der Elternlinien in bezug auf die Anzahl der Fruchtstände und Hülsen erwiesen sich als gute Basis für die Einschätzung ihrer allgemeinen Kombinationseignung. Es wurden additive Genwirkungen mit partieller Dominanz bis Superdominanz fest-gestellt. Hohe Fruchtstands- und Hülsenanzahl scheint auf rezessiven Genen zu beruhen.

     

Characteristics and inheritance of radiation-induced mutations in barley II. Two short-awned mutations

Two mutations were obtained in a two-rowed, spring-type barley variety, Asahi No. 5. KM 114 was obtained in the X₂ population of X-irradiated dormant seeds (15 Kr) and KM 218 was found in X₂ of gamma-irradiated seeds (15 Kr). KM 114 had very short awns, short plant height, almost normal spike size, and narrow and thinner seeds with pointed tip. The mutant gene is Mendelian recessive. KM 218 plants were normal or slightly taller, had somewhat larger spike, with somewhat longer rachis internodes, medium-long awn, and slightly longer, narrower and thinner kernel than those of the parental variety. At maturity, grains are exposed in many seeds (semi-naked kernels). This mutant also has a conspicuous diagnostic trait; the abnormal development of rachilla into extra florets, some of which set seeds. This mutant gene is also Mendelian recessive. Genes for these two mutants are not allelic and are inherited independently as indicated in F₂ and F₃ analyses. Genes of these two mutations will serve as good marker genes in genetic and linkage studies in barley, because their character expression is consistent and the recessive homozygotes are viable and fertile.     

Avirulent mutants ofMacrophomina phaseolina andAspergillus fumigatus initiate infection inPhaseolus mungo in the presence of phaseolinone; levamisole gives protection

To evaluate the role of phaseolinone, a phytotoxin produced by Macrophomina phaseolina, in disease initiation, three nontoxigenic avirulent mutants of the fungus were generated by UV-mutagenesis. Two of them were able to initiate infection in germinating Phaseolus mungo seeds only in the presence of phaseolinone. The minimum dose of phaseoli-none required for infection in 30% seedlings was 2 5 mg/ml. A human pathogen, Aspergillus fumigatus was also able to infect germinating seeds of P. mungo in the presence of 5 mg/ml concentration of phaseolinone. Phaseolinone seemed to facilitate infection by A. fumigatus, which is not normally phytopathogenic, by reducing the immunity of germinating seedlings in a nonspecific way. Levamisole, a non-specific immunopotentiator gave protection against infection induced by A. fumigatus at an optimum dose of 50 mg/ml. Sodium malonate prevented the effects of levamisole.     

Interactive effect of heavy metals and temperature on the growth,and chlorophyll,saccharides and soluble nitrogen contents inPhaseolus plants

The effect of combinations of different concentrations of copper (Cu) and mercury (Hg) ions with different constant temperatures (T) onPhaseolus vulgaris plants was studied. Criteria investigated included shoot and root length, dry mass, chlorophyll content (Chl) and stability index (CSI), and contents of soluble (SS) and hydrolysable saccharides (HS), soluble proteins (SP) and total free amino acid (AA). Each of the factors (T, Cu and Hg) significantly affected the parameters tested with exception of T effect on Chlb content as well as on Chla/b ratio. Bifactorial interactions (T×Cu) or (T×Hg) were also significant, except the interaction (T×Hg) in shoot elongation, Chlb content and Chla/b ratio. Statistical treatment of the data lead to three findings: (1) temperature was dominant in affecting CSIa, shoot AA and root SS, (2) Cu and Hg had the predominant effect on growth parameters and Chl content, and (3) interactions (T×Cu and T×Hg) were dominant in affecting CSIb, shoot SP, and root HS.     

Organophosphate induced chlorophyll mutations in Hordeum vulgare

Summary Ten Organophosphorus (OP) insecticides are tested for their genetic toxicology in the Hordeum vulgare system. Of these, 8 OPs induced chlorophyll mutations of which 6 are new discoveries.     

Detection of minisatellite sequences inPhaseolus vulgaris

An improved procedure for detecting minisatellite sequences inPhaseolus vulgaris is described. Both M13 protein III tandem repeat and the 33.15 human mini-satellite sequences revealed polymorphisms with a high number of sharp bands after digestion of genomic DNA withHae III,Hinf I, orTaq I. Improved resolution of the numerous restriction fragments detected by these probes is accomplished by one or more of the following: varying agarose concentration, using high SDS hybridization buffer, exposure of the autoradiograph without intensifying screens, and transfer of the autoradiograph to electrophoresis paper. Increased stability of the DNA-DNA hybridizations with these heterologous probes is obtained by reducing hybridization temperature. Labeling probes with the polymerase chain reaction can accentuate some restriction fragments depending upon the radiolabeled nucleotide used.     

Cytoplasmic inheritance of erythromycin resistant mutations in Paramecium aurelia

Summary Erythromycin inhibits the growth of wild type Paramecia and eventually kills the cells. 24 erythromycin resistant mutants (22 U.V. induced, 2 spontaneous) have been isolated. They fall into att least three phenotypic classes on the basis of their level of resistance and of thermosensitivity.Genetic analysis of three mutants shows that the resistance character is cytoplasmically inherited, as evidenced by its clonal inheritance, its transfer through cytoplasmic bridges and its non-segregation at meiosis.The results suggest that these mutants may be mitochondrial mutants analogous to those described in yeast.     

Propensity for paternal inheritance of de novo mutations in Alexander disease

De novo dominant mutations in the GFAP gene have recently been associated with nearly all cases of Alexander disease, a rare but devastating neurological disorder. These heterozygous mutations must occur very early in development and be present in nearly all cells in order to be detected by the sequencing methods used. To investigate whether the mutations may have arisen in the parental germ lines, we determined the parental chromosome bearing the mutations for 28 independent Alexander disease cases. These cases included 17 different missense mutations and one insertion mutation. To enable assignment of the chromosomal origin of the mutations, six new single nucleotide polymorphisms in the GFAP gene were identified, bringing the known total to 26. In 24 of the 28 cases analyzed, the paternal chromosome carried the GFAP mutation (P<0.001), suggesting that they predominantly arose in the parental germ line, with most occurring during spermatogenesis. No effect of paternal age was observed. There has been considerable debate about the magnitude of the male to female germ line mutation rate; our ratio of 6:1 is consistent with indirect estimates based on the rate of evolution of the sex chromosome relative to the autosomic chromosomes.     

Environmentally induced epigenetic transgenerational inheritance of sperm epimutations promote genetic mutations

A variety of environmental factors have been shown to induce the epigenetic transgenerational inheritance of disease and phenotypic variation. This involves the germline transmission of epigenetic information between generations. Exposure specific transgenerational sperm epimutations have been previously observed. The current study was designed to investigate the potential role genetic mutations have in the process, using copy number variations (CNV). In the first (F1) generation following exposure, negligible CNV were identified; however, in the transgenerational F3 generation, a significant increase in CNV was observed in the sperm. The genome-wide locations of differential DNA methylation regions (epimutations) and genetic mutations (CNV) were investigated. Observations suggest the environmental induction of the epigenetic transgenerational inheritance of sperm epimutations promote genome instability, such that genetic CNV mutations are acquired in later generations. A combination of epigenetics and genetics is suggested to be involved in the transgenerational phenotypes. The ability of environmental factors to promote epigenetic inheritance that subsequently promotes genetic mutations is a significant advance in our understanding of how the environment impacts disease and evolution.     

Effects of sodium acetate and sodium chloride on EMS-induced chlorophyll mutations in barley

Sodium acetate solutions to which sodium chloride was added, and acetate or chloride alone have been used as pre-, simultaneous, and post-treatment of dry and pre-soaked seeds of barley to study their effect on the types and frequencies of ethyl methanesulphonate (EMS)-induced chlorophyll mutations in spring barley, variety Elsa, and winter barley, varieties $\text{436}\text{35}$ and Ager. Application of acetate/chloride on dry seeds before or simultaneously with EMS both resulted in the frequency of chimeral plants with chlorophyll-deficient sectors in M₁ and chlorophyll mutants in M₂ approximately being halved as compared with the controls (EMS treatment alone).An opposite effect was observed after simultaneous treatment with acetate/ chloride and EMS (pH 4.5 and pH 7.0) and application of acetate/chloride after EMS treatment of pre-soaked seeds. In this case the mutagen sensitivity, i.e. the frequency of chimeral plants with induced chlorophyll-deficient sectors in M₁ and of chlorophyll mutants in M₂, was approximately doubled as compared with the control.Separate application of both acetate or chloride as a simultaneous treatment with EMS resulted also in an increase in the chlorophyll mutation frequency as compared with EMS treatment alone.Based on these results some aspects of the acetate/chloride effect are briefly discussed.     

Linkage relationships of recessive chlorophyll mutations inArabidopsis thaliana (L.)Heynh

A new method enabling to localize recessive alleles controling lethal embryonal or chlorophyll mutations in linkage groups has been devised and verified. The information on the linkage was obtained in B₁ in repulsion after the crosses with recessive visible markers representing the individual linkage groups. The distinction of four B₁ genotypes was achieved by means of Müller's embryotest. Altogether eight mutant alleles were localized. The allelesch 2411, ch 4062 andX 3 are carried by the first linkage group, the allelesM 33 andM 25 by the third and the allelech 1378 by the fourth linkage group. The mutant allelesch 42 andM 4–6–18 showed the linkage with the markers of the fifth and the sixth linkage groups simultaneously. The possibilities of further development and use of this method are discussed.     

Forces involved in retention and movement of non-metabolic strontium inPhaseolus vulgaris

Summary Deposition of non-metabolic strontium was studied in tops of bean plants using Sr-89 as a tracer. Test solutions contained 2, 4 dinitrophenol as a metabolic inhibitor. Roots were severed from the plants to allow direct access of solutions into the plant top.The stem contained an efficient trapping mechanism for strontium, and removed the bulk of ion from the ascending stream soon after it entered the stem. Strontium buildup in the hypocotyl base adhered to the Freundlich gas equation. The process was to some degree reversible. These findings suggest that strontium binding involved electrostatic adsorption to charged sites along the route of upward movement. The significance of electrostatic retention on acropetal movement of strontium was discussed.Work performed under U.S. Atomic Energy Commission Contract AT(30-1)2117. Contribution number19 of the Storrs Agricultural Experiment Station, Storrs, Connecticut, U.S.A.     

The effect of NaCl on water relations,chlorophyll, and protein and proline contents of two cultivars of blackgram (Vigna mungo L.)

The physiological basis of salt tolerance of two cultivars of blackgram, cv Candhari Mash (relatively salt tolerant) and cv Mash 654 (salt sensitive), was assessed in salinized sand culture at the flowering stage. Increasing NaCl concentration in the rooting medium significantly reduced the chlorophyll a, chlorophyll b, and total chlorophyll, leaf water potential (Ψ_w), leaf solute potential (Ψ_s), and leaf turgor potential (Ψ_p) in both the cultivars. Leaf protein and proline content was increased as a result of increasing salt concentration in both cultivars. High salt concentrations had no significant effect on the seed protein content of both cultivars. At high salinities, cv Candhari Mash had significantly greater chlorophyll a, chlorophyll b and total chlorophyll, leaf water potential, solute potential, and turgor potential than cv Mash 654, but the latter had greater leaf proline content than cv Candhari Mash. Cultivars did not differ significantly for both leaf and seed protein contents. The relatively salt tolerant cv Candhari Mash maintained high leaf water potential and turgor potential to resist salt injury. Leaf proline content had negative correlation with salt tolerance in blackgram.     

A monomeric protein with hemagglutinating activity from seeds of Vigna mungo (Phaseolus mungo).

Black gram (Vigna mungo) seeds are shown to contain a lectin with certain unusual features. The lectin agglutinates only trypsinized red cells, and its sugar specificity is complex as none of the common sugars, oligosaccharides or complex polysaccharides exhibit any affinity for the lectin. The purified lectin has a molecular weight of 58 kDa and is a monomer. Unlike other plant lectins, antibodies to the P. mungo lectin do not exhibit any immunological cross reactivity. The clot forming ability of the lectin is unusual in that the clot once formed is rapidly disaggregated indicated that it induces, as yet undefined, certain membrane alterations.     

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.     

Species relationships inPhaseolus: Electrophoretic analysis of seed storage proteins

Relationships among storage proteins in seeds from cultivars and primitive accessions of the four economically most important species ofPhaseolus — P. vulgaris, P. coccineus, P. acutifolius andP. lunatus — were studied. Analysis of SDS-polyacrylamide gel electrophoretic patterns of storage seed proteins revealed common characteristics in the major groups of polypeptides forP. vulgaris, P. coccineus andP. acutifolius, while clear differences existed between thesePhaseolus species and P.lunatus.