CREA Journals (Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria)
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Influence of Testers and Watering Regimes on Combining ability and Heterosis of Maize Top Crosses
Full text linkThirty-six top crosses of white maize were produced as the combinations of four male testers and nine newlydeveloped inbreds as female parents. The four testers included an inbred, a single cross, a three-way cross, anda synthetic variety. The parents and crosses were evaluated in two separate field irrigation trials to explore theextent of general combining ability and heterosis of crosses using narrow, medium, and broad base testers undernormal and stressed watering regimes. Watering regimes and genotypes as sources of variation of combinedanalysis were highly significant for all traits. The (Parents vs. Crosses) with watering regimes interaction possessedhighly significant mean squares for dates of tasseling and silking. Significant negative GCA effects were recordedfor tasseling date and silking date under both conditions. The grain yield of crosses varied differently betweenregimes. Two testers (I.272 and G.2) and two lines (I.276 and I.278) recorded significant negative GCA effects (favorable)for dates to tasseling (TD) and silking (SD) under both watering regimes. The SC.10 (as tester) and threefemale lines (I.274, I.277, and I.281) exhibited significant positive (unfavorable) GCA effects on flowering dates underboth conditions. Variable GCA effects for ASI were observed among the tested maize genotypes, particularlyunder normal conditions. However, under-stressed one, all tested genotypes showed insignificant GCA effectsfor ASI except I.272, which may be shorted the ASI. Out of thirty-six top crosses, thirty and twenty-eight crossesrecorded significantly unfavorable (favorable) heterosis under normal irrigated trial comparing to twenty-two, andtwenty-one crosses in stressed watering regime for TD and SD, respectively. However, for ASI, eleven and ninecrosses were significantly showed favorable flowering intervals than corresponding mid-parents under normal andstressed conditions respectively. For grain yield per plot about 25% significant superiority in performance of alltop crosses over corresponding mid-parents was recorded under either normal or stress conditions. The investigatedten inbred lines may be of great benefit for hybrid water-saving maize breeding program. Narrow geneticbase tester (I.272) resulted in favorable heterosis of crosses and could be recommended in advanced generationsof homozygosity, whereas mostly based ones may be valid for screening during the first generations of selfing
Genotype – environment interaction for seed yield of maize hybrids and lines using the AMMI model
Full text linkThe objective of this study was to assess genotype by environment interaction for seed yield in maize hybrids andlines growing in Western Poland using the additive main effects and multiplicative interaction model (AMMI). Thestudy comprised 32 maize genotypes (13 F1 hybrids and their 19 parental lines), evaluated in four environments(two locations in two years). Seed yield ranged from 2.50 t/ha (S311 in Łagiewniki 2013) to 18.31 t/ha (Popis inŁagiewniki 2014), with an average of 8.41 t/ha. The Popis hybrid had the highest average seed yield (15.53 t/ha),and the S56125A line had the lowest (3.65 t/ha). The average seed yield per environments also varied from 6.60t/ha in Łagiewniki 2013, to 9.95 t/ha in Smolice 2013. AMMI analyses revealed significant genotype (G) and environmental(E) effects as well as GE interaction effect with respect to seed yield. The analysis of variance explained14.59% of the total seed yield variation by environment, 77.41% by differences between genotypes, 6.50% by GEinteraction, and 1.50% by error. The Blask, Brda and Bejm hybrids are recommended for further inclusion in thebreeding program because of their stability and high averages of seed yields
THE PRESENT PEST STATUS OF EUCALYPTUSSAP-SUCKERS AND GALL WASPS IN CAMPANIA (ITALY)
Full text linkap-suckers and gall wasps may be a severe phytosanitary problem for several Eucalyptusspecies, particularlyfor the red gum E. camaldulensis, the most widely cultivated Australian native tree species worldwide. This paperreviewed the harmfulness of some of these invasive pests established in Campania, and provides new information abouttheir pest statu
Phenotypic variation in grain mineral compositions of pigmented maize conserved in indigenous communities of Mexico
Full text linkIn recent decades, pigmented corn has aroused great interest due to its contributions of bioactive compoundsand nutritional elements for the improvement of health. To evaluate the mineral grain contents in a pigmented corncollection from Oaxaca, Mexico, 57 accessions from indigenous communities and three commercial varieties weregrown in two cultivation locations. A random grain sample was obtained from the crops, and the Cu, Fe, Mn, Zn, P,Mg, K, Ca, Na, and S contents were quantified using an optical emission spectrophotometer with inductively coupledplasma (ICP-OES). The cropping localities significantly influenced the mineral contents. Likewise, significantdifferences were observed between accessions, groups of pigmented grains, and accession-locality interactionsexcept for zinc. The groups of pigmented grains interact with Cu, Fe, Ca, and Na in the environment. Among theaccessions, high variation was observed in all elements except for Zn. The results show that a breeding programcan be initiated for the outstanding blue, red, and yellow grain accessions
Genotype By Environment Interaction and Stability Analysis for Maize Hybrids in North Western Himalayas Ecology
Full text linkGenotype (G) x Environment (E) interaction of 25 medium maturity maize hybrids tested at three environments inNorth-Western Himalayas was analyzed to identify stable high yielding hybrids for mid-hill conditions. The G x Einteraction was studied using different stability statistics viz; Additive main effects and multiplicative interaction(AMMI), AMMI stability value (ASV), rank-sum (RS), and yield stability index (YSI). Combined analysis of varianceshows that genotype, environment, and G x E interaction is highly significant. This indicated the possibility of selectionof stable genotypes across the environments. The results of the AMMI analysis showed that the first two principalcomponents (PC1-PC2) were highly significant (P<0.05). The partitioning of TSS (total sum of squares) exhibitedthat the environment effect was a predominant source of variation followed by genotypes and G×E interaction,suggesting the possible existence of different environmental groups. The first two interaction principal componentaxis (IPCA) cumulatively explained 82.87% of the total interaction effect. The study revealed that G11 and G7 werefound to be stable based on all stability statistics and GGE biplot assessment. Based on GGE biplots, it is concludedthat E3 is the best environment for testing the hybrids for more extensive adaptability and E2 and E1 locations can beused to identify location-specific hybrids. Grain yield is positively and significantly correlated with rank-sum (RS)And yield stability index (YSI). The above-mentioned stability statistics could be useful for identification of stablehigh yielding genotypes, whereas, GGE biplots facilitated visual comparisons of high yielding genotypes acrossthe multi-environments
CONTRIBUTION TO THE KNOWLEDGE OF BITING MIDGES(DIPTERA CERATOPOGONIDAE) OF SARDINIA, ITALY
Full text linkThe ceratopogonid fauna of northern Sardinia (Italy) was investigated using black light traps. The study wascarried out in six localities from June to August 2015. A total of 3,879 ceratopogonids were collected and 40 speciesbelonging to 8 genera were identified. The most abundant genus was Culicoides(96%) followed by Forcipomyia(1.5%), Bezzia(1.2%) and Dasyhelea, Atrichopogon, Alluaudomyia, Stilobezziaand Brachypogon(each <1%). Sevennew species for Italian fauna were recorded: Forcipomyiabipunctata, Forcipomyiapsilonota, Culicoides achrayi,Culicoidescameroni, Culicoidescorsicusand Bezzia pygmaea. Stilobezziasahariensiswas reported for the first time inEurope
Identification of superior doubled haploid maize (Zea mays) inbred lines derived from high oil content subtropical populations
Full text linkHigh oil maize (HOM) hybrids, adapted to subtropical regions are needed to meet existing requirements forindustrial and livestock purposes. Recently, the doubled haploid (DH) breeding technology is applied to reduceconsiderably the time to generate homozygous maize lines, however, information of heterotic response, per seproductivity, stress, disease reaction, and adaptation to different environments are not known. In this work, fieldevaluations of per se and testcross high oil content DH lines adapted for subtropical environments were studiedto identify superior DH lines with good heterotic response and agronomic characteristics. White and yellow kerneltest crosses were formed using the different heterotic population as testers from which DH lines were derived.Test crosses were evaluated at three locations in Mexico. Superior DH lines from each tester presented highGCA effects through test crosses, with a range of grain yield across locations of 12.8 to 10.4 Mg ha-1 and 11.1to 9.1 Mg ha-1 respectively. Per se DH lines were observed and screened for adaptation, productivity, diseasereaction and other agronomic traits in five locations/year environments. Per se DH lines screening process acrossenvironments was able to obtain information for adaptation, productivity, and healthiness. Also of DH lines withhigh response of GCA, information regarding heterotic groups, and DH lines oil content determination was usedto identify outstanding DH lines for developing HOM high-yielding hybrids adapted for subtropical regions, withfewer costs and time. This research demonstrated that it was feasible to identify subtropical elite DH lines withhigh oil content
FIRST RECORD OF RICANIA SPECULUM(WALKER, 1851) (HEMIPTERA RICANIIDAE)FROM VENETO, PIEDMONT AND LATIUM REGIONS AND NEW HOST PLANTS
Full text linkThe distribution of Ricania speculum(Walker, 1851) (Hemiptera Fulgoromorpha Ricaniidae) in Italy was updatedand the species was recorded for the first time in Veneto (2017), Piedmont (2018) and Latium (2018) regions. Theoccurrence of this species in Sardinia, previously recorded, is here excluded. Moreover, 33 new host plants belonging to 29families resulted to be attacked by this alien invasive species confirming its outstanding polyphagy
IMMUNOMODULATION OF HOUSE FLIES EXPOSED TO AZADIRACHTIN
Full text linkIn this study the lethal and sub-lethal effects of azadirachtin on adult house flies, and the main variations in theirimmune-related gene expression levels were detected. Flies acquiring azadirachtin by ingestion showed differentdegrees of susceptibility depending on concentration and time of exposure to this compound, with LC50valuecorresponding to 101.14 µg/ml, after five days of exposure to a dose of 7.5 µl/fly/day. Flies surviving ingestion of sub-lethal concentrations showed significant decrease in their lifespan and reproductive performance, including fecundityand percentage of egg hatching.A significant immune-stimulation effect of lower azadirachtin concentrations (25 µg/ml), and a generalimmunosuppression of most AMPs (i.e. attacin, cecropin, defensin,diptericin and muscin) at higher concentrationlevels (100 µg/ml) were observed. This study highlights the immunodeficiency potential of azadirachtin, providing new insights into understandingthe physiological response of Musca domesticato this botanical compound at the molecular level
Comparative performance and genotype by environment interaction effects on grain yield of single and multiple crosses of maize (Zea mays L.)
Full text linkA set of 256 entries involving seven parents and their single, three-way and double crosses derived through half diallel were evaluated along with private/public hybrids for grain yield in a balanced lattice design at three environments during kharif 2015. ANOVA revealed that TWC × Parents, DC × TWC, DC × SC, DC × Parents, SC × Parents interaction were significant at all the locations. Mean squares for singles, double and three-way crosses were similar at Hyderabad, Karimnagar locations and at Palem location with high mean squares for three-way crosses. Data were also obtained on the variety × environment interaction patterns for the three types of crosses. Significant interaction deviate was higher for double crosses followed by three-way crosses and single crosses.Average yield of double crosses was 37 kg ha-1 greater than that for single crosses, and the average for single crosses was 143 kg ha-1 greater than for three-way crosses. The range of single crosses was 483 kg ha-1 less than that for three-way crosses and 30 kg ha-1 greater than that for double crosses. Stability analysis for grain yield showed significant genotype × environment interaction in all the three classes of hybrids and the crosses (BML-51 × BML-10) × (BML-6), (BML-51 × BML-32) × (BML-13 × BML-6) and (BML-13 × BML-7) × (BML-10 × BML-6) were found to be stable, had average response to all environments, hence these are need to be exploited to combat biotic and abiotic stresses arising through climate change