The effect of thiram concentration on the spore germination of isolates of Cochliobolus carbonum

Inhibition of spore germination of selected isolates ofCochliobolus carbonum was studied with increasing concentrations of thiram. Isolate differences were detected for the TMTD polymodal curve. This difference was shown to be heritable and independent of tolerance to thiram as indicated by vegetative growth. The polymodal TMTD curve of spore germination inhibition inC. carbonum may result from two (or more) thiram sensitive loci each genetically conditioned independently.A joint contribution of the Department of Plant Pathology and the Pesticides Research Laboratory. The Pennsylvania State University, University Park 16802.     

Genetic analysis of resistance to whitebacked planthopper in twenty-one varieties of rice,Oryza sativa L.

Summary The inheritance of resistance to whitebacked planthopper Sogatella furcifera (Horvath) was studied in 21 rice varieties. Reactions of F₁; F₂ and F₃ progenies of the crosses of 21 resistant varieties with the susceptible variety TN 1 revealed that a single dominant gene governs resistance in Mushkan 41, Santhi, Siahnakidar 195, SM2-34, Tirisurkh 251, Zirijowaian 245, 18, 24A, 39, 76 S, 78, 180, 213 B, 267, 293, CI 6037-4, NP97, S39 JKW and Bansphul. In varieties 65 and 274 A, resistance is governed by one dominant and one recessive gene which segregate independently of each other. Tests for allelism with the Wbph 1 gene originally identified in N 22 revealed that the dominant gene present in all the test varieties is the same as Wbph 1. Further studies are required to determine the allelic relationships of the recessive gene found in varieties 65 and 274 A.     

The incorporation and characterization of powdery mildew resistance from Aegilops longissima in common wheat (T. aestivum L.)

Summary In the progeny of a hybrid between monotelosomic line 3B of Chinese Spring wheat and Chinese Spring — Aegilops longissima ditelosomic addition line G a cytologically stable strain was selected consisting of 20 wheat chromosome pairs, one pair of telosomic chromosome 3BL and one pair of telosomic longissima chromosome G. Inoculating Chinese Spring — Aegilops longissima addition and substitution lines with ten different powdery mildew isolates, partial resistance was observed. The infection grade as well as the number of spores/cm² leaf area were significantly reduced.     

Variability and genetics of tolerance for aluminum toxicity in rice (Oryza sativa L.)

A study was undertaken to investigate the variability among lowland rice cultivars and the mode of gene action of aluminum (Al) toxicity tolerance in rice. Pregerminated seeds were grown in a nutrient solution containing 30 ppm Al and in normal nutrient solution, and relative root length (RRL) was determined at the 14-day-old stage to characterize genotypes for tolerance. Sixty-two traditional rice cultivars grown on lowland acid sulfate soil areas of Asia and West Africa were tested. Tolerant varieties Azucena, IRAT104, and Moroberekan, moderately sensitive IR29 and IR43, and sensitive IR45 and IR1552 were used to investigate the genetics of tolerance by diallel analysis. Of the 62 cultivars tested, only 3 were found to be sensitive to A l toxicity. Among the tolerant cultivars identified, 11 (Siyam Kuning, Gudabang Putih, Siyam, Lemo, Khao Daeng, Siyamhalus, Bjm-12, Ketan, Seribu Gantang, Bayer Raden Rati, and Padi Kanji) were found to possess higher levels of tolerance than the improved tolerant upland cultivar IRAT104. Diallel analysis revealed that high RRL is governed by both additive and dominance effects with a preponderance of additive effects. The trait exhibited partial dominance, and one group of genes was detected. Heritability was high, and environmenal effects were low. Findings suggest that when breeding for A1 toxicity tolerance, selection can be made in early generations. The pedigree method of breeding would be suitable. Combining ability analysis revealed the importance of both general combining ability (GCA) and specific combining ability (SCA) in the genetics of A1 toxicity tolerance in rice. GCA was more prevalent than SCA. Tolerant parens Azucena, IRAT104, and Moroberekan were the best general combiners. The presence of reciprocal effects among crosses suggested the proper choice of parents in hybridization programs. Results indicated that Azucena, IRAT 104, and Moroberekan should be used as the female in crosses for A1 toxicity tolerance.     

Frequency and spectrum of chlorophyll mutants induced in rice by chemical mutagens

Summary Dry seeds of rice varieties T(N)1, IR 8 and Sona, with stabilised moisture content and presoaked in distilled water, were treated with chemical mutagens MMS, dMS, dEMS and dES with the purpose of evaluating chlorophyll mutation frequency and spectrum. In the M₂ generation, mutants occurred in 24 lines of 'T(N)1; 94 lines of IR 8 but only in six of Sona. They include albino, viridis, xantha and other categories of which viridis was predominant. dES was found to be most effective of all mutagens used in all the three varieties and varietal differences were observed.     

The influence of lactation products on the temporal expression of histo-blood group antigens in the intestines of suckling pigs: lectin histochemical and immunohistochemical analysis

Summary Lectins and carbohydrate-specific monoclonal antibodies were used as cytochemical probes to investigate the possible influence of lactation products on the expression of intestinal membrane and secretory glycoconjugates in suckling piglets. Two different lactational regimes were compared; the first involved normal rearing of piglets for 8 weeks on a single dam and the second involved repeated cross-fostering of littermates onto recently farrowed sows, thereby restricting them to early milk. Five histo-blood group phenotypes were recognized within the piglet population: two immature phenotypes, O immature or Oi and A immature or Ai, and three mature forms, O, A and -. Under the normal suckling regime the transition from immature to mature OA phenotypes was evident at the fifth weekpost partum. However, in the repeatedly cross-fostered piglets this transition was evident much earlier at 3 weekspost partum. It is suggested that qualitative or quantitative variations in milk composition during the sow's lactation may significantly influence the expression of intestinal histo-blood group antigens in her suckling young.Abbreviations GalNac N-acetylgalactosamine - Gal Galactose - GlcNac N-acetylglucosamine     

Genetic analysis of brown planthopper resistance in twenty varieties of rice,Oryza saliva L.

Summary The inheritance of resistance to brown planthopper, Nilaparvata lugens (Stol.), of 20 rice cultivars was studied. Single dominant genes that are allelic to Bph 3 condition the resistance in cultivars Ptb 19, Gangala (Acc. 7733), Gangala (Acc. 15207), Horana Mawee, Kuruhondarwala, Mudu Kiriyal and Muthumanikam. Single recessive genes that are allelic to bph 4 govern the resistance in cultivars Gambada Samba, Heenhoranamawee, Hotel Samba, Kahata Samba, Kalukuruwee, Lekam Samba, Senawee, Sulai, Thirissa and Vellai Illankali. The resistance in Ptb 33, Sudu Hondarwala, and Sinna Sivappu is governed by one dominant and one recessive gene which segregate independently of each other. The dominant resistance genes in these cultivars appear allelic to either Bph 1 or Bph 3. Similarly, the recessive genes in these cultivars seem allelic to either bph 2 or bph 4. Further investigations are needed to conclusively determine the allelic relationships of resistance genes in Ptb 33, Sudu Hondarwala and Sinna Sivappu.     

Nucellar callus of ‘Femminello’ lemon,selected for tolerance toPhoma tracheiphila toxin,shows enhanced release of chitinase and glucanase into the culture medium

Phoma tracheiphila is the causative agent of the disease mal secco. Citrus cultivars differ substantially in respect to their sensitivity to the pathogenP. tracheiphila and its toxin. Some cultivars (e.g., Femminello lemon) are inherently sensitive while others (e.g., Tarocco orange) are tolerant. Cell lines derived from nucellar tissue of Femminello, Tarocco and a cell line selected for tolerance to the fungal toxin (Femminello-S) were used to study host-pathogen interaction. Our results showed that calli or conditioned media of Tarocco and Femminello-S inhibited the size of co-cultivated fungal colonies when compared to Femminello. In addition, conditioned medium of Tarocco as well as FemminelloS, but not Femminello, promoted bursting of hyphal tips. A ten-fold increase in chitinase and glucanase enzymatic activity, as evaluated by radiometric assay and laminarin hydrolysis respectively, was detected in Femminello-S extracellular extracts as compared to Femminello. An increase in chitinase was also shown by immunoblot analysis. Our findings suggest a positive correlation between the presence of chitinase and glucanase in the conditioned media of the cultured cells and the tolerance of those cells toP. tracheiphila toxin.     

Diallel analysis of submergence tolerance in rice,Oryza sativa L.

Summary The genetics of submergence tolerance in rice was studied in a 10 × 10 half-diallel cross set involving 10 lowland rice varieties, four of which were tolerant (FR13A, FR43B, Kurkaruppan, and Goda Heenati) and the remaining six were nontolerant (RD19, IR42, IR17494-32-1, IR19672-24-3, Jagannath, and CR1009). Estimates of genetic parameters following Hayman's method showed significant additive and nonadditive gene action and the latter appeared to be solely due to dominance. Narrow sense heritability (0.70) indicated that additive gene effects were more important in the inheritance of the trait. Tolerance was dominant over nontolerance and the average dominance was within the range of incomplete dominance. Dominant alleles were more concentrated in the three tolerant parents, FR13A, Kurkaruppan, and FR43B in that order. Wr/Vr graphic analysis suggested the involvement of both major and minor genes. Combining ability analysis by Griffing's method also indicated significance of both additive and nonadditive effects, and the former appeared to be more important than the latter. The hybrids involving FR13A with RD19, IR42, and IR17494-32-1, and those of Kurkaruppan with RD19 and CR1009 appeared to be promising for incorporating an adequate level of tolerance to submergence into lowland rice cultivars.     

Inheritance of callus formation ability in anther cultures of rice,Oryza sativa L.

Summary Inheritance of ability to form callus in rice anther culture was studied using the diallel technique. Anthers containing uninucleate microspores from two japonica cultivais (Minehikari and Taipei 309), two indica cultivars (Mingolo and Suweon 290), and 12 F₁'s of the diallel crosses involving these four parents were cultured on Chaleffs R₂ medium and evaluated for callus induction. The parents showed significant differences in anther callus formation, from 41.9% (Taipei 309) to 0% (Suweon 290). Callus induction ability was inherited as a recessive character conditioned by a single block of genes. Additive gene effects were predominant. The japonica types seemed to be good combiners for callus induction. The order of dominance among the four parents was Suweon 290, Mingolo, Minehikari and Taipei 309.     

Ecological theories and Dutch nature conservation

This paper aims to achieve insight into various ecological theories in the Netherlands which have different, and sometimes opposing, views on the conservation of nature. Interviews, publications and archival research brought to light four separate theories: vitalistic/holistic, dynamic, cybernetic and chaos. Diversity is reached through stability according to vitalistic/holistic and cybernetic theories, but through change and instablility according to the dynamic and chaos theories. These two groups are working apart, and continue to have their own ideas. Prediction of the future is only possible with the vitalistic/holistic and cybernetic theories. Ecologists who adhere to these theories feel responsible and able in different ways to change ecological nature towards desirable end goals. The other two theories, dynamic and chaos, appear to be less activist.     

Effect of giving insulin and adrenalin alternately on changes in the level of blood glucose in chickens of different breeds

Summary Differences in reaction to exogenous insulin and adrenalin were studied among chickens of Leghorn, White Rock and Rhode Island Red breeds, using level of blood glucose as indicator of the reaction to hormones. It was found that: 1.) The physiological quantity of glucose in blood in chickens of the three breeds ranged from 157 to 194 mg %. 2.) The reaction of chickens to insulin and adrenalin given alternately, measured by changes of blood glucose, differed according to the breed. The smallest reaction to hormones was in Leghorn, the biggest in White Rock. 3.) The chickens of Leghorn and Rhode Island Red breeds, as well as Leghorn and White Rock breeds, differed significantly in maximal glucose level after adrenalin, 4.) The correlation between the normal quantity of blood glucose and the body weight of birds appeared highly significant in cockerels of all three races combined.     

Variation in the karyotype of three cultivars of Narcissus tazetta L. (Amaryllidaceae)

Three cultivated varieties of Narcissus tazetta, Grand Soleil d'Or, Chinese Sacred Lily and Cypri, are triploid (2n = 3x+30) with the basic number 10. Grand Soleil d'Or has three homomorphic sets, each comprising 2 long submetacentrics, 4 long acrocentrics and 4 short acrocentrics. Karyotypes of the other two varieties are heteromorphic. Both possess one telocentric satellited chromosome. In addition, Cypri shows translocation between two chromosomes belonging to the seventh and eighth triplets. The number of secondary constrictions varies between 3 (Chinese Sacred Lily) and 4 (Grand Soleil d'Or and Cypri) which is also the number of nucleoli observed in the respective varieties.     

Involvement of abscisic acid in bulb dormancy of Allium wakegi Araki. II. A comparison between dormant and nondormant cultivars

The content of abscisic acid (ABA) in bulbs of two Allium wakegi Araki cultivars, Kiharabansei No. 1 (dormant type) and Ginoza (nondormant type), was similar and changed similarly during the development and storage of the bulbs. It increased during bulb development, reached a maximum shortly after bulb harvesting, and gradually decreased during bulb storage. The bulbs of Kiharabansei No. 1 showed dormancy correlated with the change in ABA content, but those of Ginoza did not show significant dormancy throughout the experimental period. The ABA content in the buds of dormant bulbs of Kiharabansei No. 1 did not change after planting of bulbs, but that of nondormant bulbs of Ginoza planted on the same day rapidly decreased after planting. Application of ABA to bulbs delayed sprouting of both cultivars, but dormant bulbs of Kiharabansei No. 1 had higher sensitivity to ABA than the bulbs of Ginoza or the bulbs of Kiharabansei No. 1 partly released from dormancy. These results suggest that the decrease in the ABA content after planting (watering) and low sensitivity to ABA are correlated with the nondormancy of Ginoza.     

Mutagenic effectiveness and efficiency of EMS,DES and gamma-rays in rice

Summary Data on chlorophyll mutation frequency after treatment with EMS, DES and gamma-rays and sequential administration of gamma-rays and the two alkylating agents in three varieties of rice have been used to work out quantitatively the effectiveness and efficiency of each mutagen and combination treatment. For effectiveness, the order is EMS > DES and for efficiency it is EMS > DES > gamma-rays. In some sequential treatments (Gamma-rays + DES in IR8 and Basmati; DES + gamma-rays in IR8 and Jhona; Gamma-rays + EMS in IR8 and Basmati; and EMS + gamma-rays in IR8, Jhona and Basmati) mutation frequency is more than additive (synergistic) but these treatments are decisively less efficient because of their relatively high injurious effects in the M₁. generation. EMS induces more albinas than gamma-rays do. The mutational spectrum patterns induced by gamma-rays and DES are alike. In general, combination treatments tend to increase the frequency of albinas over other types of chlorophyll mutants.     

Molecular mapping of a new gene Rrs4 CI 11549 for resistance to barley scald (Rhynchosporium secalis)

Doubled haploid (DH) progeny from a cross between the scald susceptible barley (Hordeum vulgare L.) cultivar Ingrid and the resistant accession CI 11549 (Nigrinudum) was evaluated for resistance in the pathogen Rhynchosporium secalis (Oudem) J.J. Davis. Two linked and incompletely dominant loci confer resistance CI 11549 against isolate 4004. One is an allele at the complex Rrs1 locus on chromosome 3H close to the centromere; the other is located 22 cM distally on the long arm. The latter locus is designated Rrs4. In BC₃-lines into Ingrid from CI 2222 (another Nigrinudum) resistance seems governed by one locus close to the telomeric region of chromosome 7H, probably allelic to Rrs2. In neither case did we find any trace of the recessive gene rh8 reported to be present in Nigrinudum. Various resistance donors of Ethiopian origin designated as Nigrinudum, Jet or Abyssinian were identical to a great extent with respect to markers, but differed in resistance to different isolates of scald or in barley yellow dwarf virus (BYDV) resistance. The implications for their use as differentials in scald tests and screening of germplasm collections are discussed.     

On morphological variation in Keratella cochlearis populations from Holstein lakes (Northern Germany)

Keratella cochlearis occurs in many Holstein lakes (northern Germany) as three well defined and separated forms: cochlearis, hispida, and tecta, each showing very little variation between the lakes. The present data show that the tecta form did not originate from a Lauterborn cycle.     

Immunofluorescence localization of the epidermolytic toxin target in mouse epidermal cells and tissue

Summary An epidermolytic toxin target was observed in keratohyalin granules of sectioned epidermis by a direct fluorescence procedure using FTC-toxin, but not by an indirect procedure using sequential reaction with toxin, anti-toxin and FTC-secondary antibody. The investigation of the two procedures was extended to keratinocytes. A dispase digestion procedure yielded three fractions which corresponded to basal, spinous and granular cells according to biochemical and morphological criteria. It was shown that the direct and indirect procedures both detected the toxin target in the keratohyalin granules of granular cells, but that the indirect procedure was very insensitive. In control experiments, the profilaggrin of keratohyalin granules was detected readily in cells by a direct procedure using FTC-antiprofilaggrin but only weakly by an indirect double antibody procedure. Insensitivity to indirect procedures thus appears to be a particular property of the keratohyalin granule site. It was shown that the toxin target was readily accessible in permeable (trypsin-isolated) granular cells but inaccessible in impermeable (dispase-isolated) cells.     

An alfalfa (Medicago sativa L.) cDNA encoding an acidic leghemoglobin (MsLb3)

We have found an alfalfa cDNA clone that encodes an acidic leghemoglobin. To date, 14 alfalfa leghemoglobin clones have been identified. Five different leghemoglobin components have been biochemically defined on the basis of their pI. A higher-resolution comparison, provided by sequence data analysis, identifies six leghemoglobin classes. All 14 leghemoglobins are assigned to the six classes, which can be distributed among the five leghemoglobin components. The newly identified leghemoglobin is the only member of a sixth class of leghemoglobins, and it also is the only member of one of the acidic leghemoglobin components IV or V.     

Local motion processing in the optic tectum of the Japanese toad,Bufo japonicus

Summary The results of previous behavioral studies can be so interpreted that the prey-catching behavior in the toad is elicited if there is a local motion restricted with-in a small part of the visual field, while it is suppressed if there is a global motion over a large part of the visual field. This has led us to design experiments to answer a specific question (yet a very essential one for understanding neural processes underlying this behavior): Are there local motion detectors in the toad's visual system that are not activated by global motion over a large part of the visual field but are activated by local motion confined within a smaller part of it? The present study showed that (1) the majority of the toad's tectal neurons exhibit properties of the local motion detectors as defined above, and (2) these properties can be explained from the receptive field structure revealed in the present experiments. Based on these results, we suggest that the tectal local motion detectors are essential for the detection and localization of small moving prey-objects in the natural environment while ignoring the large moving objects or the self-induced motion of the visual field.Abbreviations ERF excitatory receptive field - G1-5 group 1–5 neurons