Acceptable Levels Of Resistance Research Articles

Light Weight CNN based Robust Image Watermarking Scheme for Security

In recent years, digital watermarking has improved the accuracy and resistance of watermarked images against many assaults, such as various noises and random dosage characteristics. Because, based on the most recent assault, all existing watermarking research techniques have an acceptable level of resistance. The deep learning approach is one of the most remarkable methods for guaranteeing maximal resistance in the watermarking system's digital image processing. In the digital watermarking technique, a smaller amount of calculation time with high robustness has recently become a difficult challenge. In this research study, the light weight convolution neural network (LW-CNN) technique is introduced and implemented for the digital watermarking scheme, which has more resilience than any other standard approaches. Because of the LW-CNN framework's feature selection, the calculation time has been reduced. Furthermore, we have demonstrated the robustness of two distinct assaults, collusion and geometric type. This research work has reduced the calculation time and made the system more resistant to current assaults.

Components of quantitative resistance to Fusarium head blight agents in durum and bread wheat plants grown under Mediterranean conditions

Fusarium head blight (FHB) is one of the major damaging fungal diseases affecting wheat production globally. As a basis for progress in devising future management strategies for FHB in wheat, it is necessary to identify resistant wheat cultivars to disease infection and determine whether their stability varies over several experimental conditions. A pot experiment under open field Mediterranean conditions over two growing seasons 2017/18 and 2018/19 was conducted to evaluate components of quantitative resistance to a set of 16 fungal isolates of four FHB species. Disease-type I resistance, disease-type II resistance as well as disease-type III resistance were compared on two Syrian durum and bread wheat cultivars varying in their FHB resistance. Douma4 (bread), rather resistant in vitro and under controlled conditions, showed greater FHB disease-type I and II resistance than Cham7 (durum), which showed a susceptibility to disease. There were no significant differences in the resistance of two wheat cultivars as measured by disease-type III. As expected, these results confirmed previous in vitro and growth chamber findings, indicating that the assessment of resistance level is repeatable and stable under several experimental conditions. Overall, the two tested wheat cultivars were shown to exhibit acceptable resistance levels to FHB infection. Differences in aggressiveness among fungal isolates and susceptibility/resistance among wheat cultivars were found, emphasizing that screening for wheat resistance to FHB requires the use of aggressive fungal isolates or a mixture of several isolates. While in the Mediterranean countries the risk of disease is progressively increasing, the preliminary data in this report show that Syrian commercial cultivars could be new resistant donors with favorable agronomical characteristics in FHB-wheat breeding programs.

Fusarium head blight resistance in F1 hybrid spring wheat

Hybrid wheat shows promise to increase yield potential, but many questions remain about the hybrid system. One of the most important is how hybrids will perform in terms of diseases such as Fusarium head blight (FHB). It is unknown if a hybrid produced from a resistant by susceptible cross will express acceptable resistance levels. This experiment tested hybrids produced from four resistant parents crossed with a common susceptible parent (2398). The results indicated that the hybrids were resistant compared with the susceptible parent and mid-parent, while they were less resistant compared with their respective resistant parent. The hybrids were between the mid-parent and resistant parent in resistance to FHB traits. This may indicate that the resistance in the hybrids may be controlled by partial dominance gene action. The findings also indicated that accumulation of more resistance genes provided improved resistance to FHB. In conclusion, successful hybrids with a good level of FHB resistance could be produced through crossing parents with contrasting resistance to this disease.

Registration of ‘CP 11‐2248’ sugarcane for Florida organic soils

Abstract‘CP 11‐2248’ (Reg. no. CV‐193, PI 692134) sugarcane (a complex hybrid of Saccharum spp.) was developed by the USDA–ARS, the University of Florida, and the Florida Sugar Cane League, Inc., and released to Florida growers for organic (muck) soils in June 2018. CP 11‐2248 was developed from a polycross made at Canal Point, FL, on 16 Dec. 2009, with a breeding line CP 06‐2664 as the female parent. The male parent was unknown and could be any one of the clones used in the polycross. CP 11‐2248 was released for commercial use as an improved sugarcane cultivar because of its acceptable levels of resistance or tolerance to brown rust, orange rust, smut, leaf scald, and mosaic. CP 11‐2248 was moderately susceptible to ratoon stunting disease and Sugarcane yellow leaf virus in Florida. Based on the results of 19 harvests of three crops (plant cane, first ratoon, and second ratoon) in the final‐stage (i.e., Stage 4) replicated yield trials carried out at seven locations with muck soils in Florida, CP 11‐2248 had equivalent or slightly higher sucrose yield than check cultivars CP 96‐1252 and CP 00‐1101. CP 11‐2248 may be poor in response to freezing temperatures based on the field tests in north Florida for temporal sucrose deterioration.

Study of some resistance mechanisms to Orobanche spp. infestation in faba bean (Vicia faba L.) breeding lines in Tunisia

The behavior of seven faba bean breeding lines toward Orobanche foetida and Orobanche crenata infestation was examined under field, pots, and in vitro conditions and compared to reference cultivars. The breeding lines presented resistance reaction to Orobanche spp. in different experiment conditions. In infested field by O. foetida, the grain yield reduction ranged from 55.7 to 83% for the breeding lines compared to 97% for the susceptible cultivar Badï. Lines L6 and L7 were the less affected by Orobanche parasitism considering severity, number of emerged Orobanche, and yield. In pots, the number of attachments varied from .6 to 3.4 and from 1.4 to 6.4 for the breeding lines against 10.4 and 12.3 for Badï inoculated, respectively, by O. foetida and O. crenata. In Petri dish experiment, Orobanche germination reached the highest rates; 69.9 and 59.7%, respectively, with O. crenata and O. foetida for Badï. For the breeding lines, it ranged from 6.3 to 44.9% for O. crenata and from 4.8 to 40.8% for O. foetida. Moreover, all breeding lines showed low tubercles number and delay in Orobanche attachments as compared to Badï. All breeding lines, except L5, maintained an acceptable level of resistance to Orobanche species manifested by a reduced Orobanche germination rate, low Orobanche number and dry weight, delay of attachments, and higher grain production compared to Badï. L5 seems to be less resistant even it behaves better than Badï in different culture conditions. The studied breeding lines could be recommended as resistance sources or candidates for varieties registrations.

Covalent Cross-Linking of Cell-Wall Polysaccharides through Esterified Diferulates as a Maize Resistance Mechanism against Corn Borers

There is strong evidence to suggest that cross-linking of cell-wall polymers through ester-linked diferulates has a key role in plant resistance to pests; however, direct experimentation to provide conclusive proof is lacking. This study presents an evaluation of the damage caused by two corn borer species on six maize populations particularly selected for divergent diferulate concentrations in pith stem tissues. Maize populations selected for high total diferulate concentration had 31% higher diferulates than those selected for low diferulates. Stem tunneling by corn borer species was 29% greater in the population with the lowest diferulates than in the population with the highest diferulates (31.7 versus 22.6 cm), whereas total diferulate concentration was negatively correlated with stem tunneling by corn borers. Moreover, orthogonal contrasts between groups of populations evaluated showed that larvae fed in laboratory bioassays on pith stem tissues from maize populations with higher diferulates had 30-40% lower weight than larvae fed on the same tissues from maize populations with lower diferulates. This is the first report that shows a direct relationship between diferulate deposition in maize cell walls and corn borer resistance. Current findings will help to develop adapted maize varieties with an acceptable level of resistance against borers and be useful in special kinds of agriculture, such as organic farming.

Novel ethylcellulose-coated pellets for controlled release of metoprolol succinate without lag phase: characterization, optimization and in vivo evaluation

The objective of this study was to develop a novel ethylcellulose (EC)-coated pellet with partial active dose as a pore former for the controlled release of water-soluble metoprolol succinate (MS) without an initial lag phase (slow/non-drug release phase). MS-layered cores with a high drug-loading efficiency (97%, w/w), a smooth surface, and an acceptable level of resistance to abrasion were first obtained by spraying a concentrated drug solution (60% w/w at 70 °C) on non-pareils in the absence of other binders. The presence of the drug in an EC coating solution significantly improved the coating process by reducing pellet stickiness. Central composite design and response surface methodology was employed to optimize and explore the effect of pore former MS level (X1) and EC coating level (X2) on the drug release. The pore former level had a positive effect on the MS release and the coating level had a negative effect. The level of X1 and X2 of the optimization were 17% and 23%, respectively, and the cumulative percent of MS released within 1 h was up to 9.2%. Accordingly, the initial lag phase associated with in vitro drug release from EC-coated pellets was absent when MS drug was used as a pore former, which was further confirmed by in vivo drug release in beagle dogs. Thus, a novel approach for the controlled release of MS from coated pellets without lag phase has been successfully developed, which is valuable for the advancement of sustained-release pellets.

Diallel analysis of turcicum leaf blight resistance in Kenyan maize lines

Exserohilum turcicum is a major constraint to maize production in the humid highlands of sub-Saharan Africa. To develop efficient cultivars, the gene action involved and genetic stability across target ecologies must be understood. A half diallel study of 12 inbred lines was conducted to assess the types of gene action involved in turcicum resistance and genetic stability across 5 locations in central and western Kenya. Both additive and non-additive gene effects were important and highly dependent on test ecologies. General combining ability accounted for 84% of the variation across locations and hence selection for resistance to turcicum should be effective if directed at disease environments. Dominant effects were less influenced by the environments, suggesting stability of turcicum resistance among hybrids. Two environments, Bukura and Kitale, were found most discriminating for the disease both among parental genotypes and among the F1 crosses. Half of lines used in this study were found to have acceptable levels of resistance. One parent, P2 (S4 80-17-2-1) had the most desirable qualities of per se resistance, general combining ability and genetic stability. Multi-locational breeding nurseries can be a useful strategy to identify turcicum resistant lines with wide ecological appeal to plant breeders. Key words: Gene action, turcicum blight, resistance, genetic stability, genotype-by-environment interaction

Identification of Resistance to Peppery Leaf Spot among Brassica juncea and Brassica rapa Plant Introductions

Brassica leafy greens (Brassica juncea L. and Brassica rapa L.) represent one of the most economically important vegetable crop groups in the southeastern United States. In the last 10 years, numerous occurrences of a leaf-spot disease on these leafy vegetables have been reported in several states. This disease, known as peppery leaf spot, is now causing serious crop losses and has been attributed to the bacterial phytopathogen Pseudomonas syringae pv. maculicola (Psm). To date, it appears that all cultivars of the Brassica leafy greens are susceptible, and available pesticides for control of this disease appear unable to reduce the disease to acceptable levels. Thus, we undertook a search for potential resistance to this disease among accessions of B. juncea and B. rapa included in the U.S. Plant Introduction (PI) collection. In greenhouse trials, we screened commercial cultivars and 672 U.S. PIs (226 B. juncea and 446 B. rapa) for resistance to Psm with artificial inoculation. Although severity of disease symptoms was significantly different among inoculated accessions, no acceptable levels of resistance were found in any of the more than 400 B. rapa accessions tested. Only two B. juncea accessions (PI 195553 and G 30988) of 226 tested had acceptable levels of resistance that might prove economically useful.

Reactions of differential rice genotypes to African rice gall midge in West Africa

Considerable diversity was observed in the reactions of 20 rice genotypes to African rice gall midge (AfRGM) at five locations in four countries in West Africa. Of 14 Oryza sativa lines studied, TOS14519 had the lowest mean plant damage; TOG7106 had the lowest mean damage among five O. glaberrima lines in the trials. The only O. sativa 2 O. glaberrima progeny in the study, WAB450-I-B-P-181-22-1- HB, showed mean damage comparable with the resistant check NHTA 8. The levels of resistance shown by the glaberrimas were better than those of the sativas. Eight genotypes could be described as possessing both stable and acceptable levels of resistance to the pest. TOG7106 and TOS14519 were rated highly stable and highly resistant. The high genotype 2 environment interaction in the reactions of the rice lines to AfRGM could not be attributed to agroclimatic or crop management factors, leaving us to suggest the possible existence of different biotypes of AfRGM in West Africa.

Characterization and Control of Garlic Rust in California.

In 1998, a devastating outbreak of rust disease severely damaged the garlic crop in California, resulting in yield losses of 51% and an economic loss of 27% to the industry. The disease also occurred in 1999 and 2000, indicating that rust may have become an annual problem in some parts of the state. The presence of urediniospores, two-celled teliospores, and telial paraphyses indicated that the pathogen was Puccinia allii. Isolates from garlic infected onion and chives, but not leek, elephant garlic, or shallot in inoculation experiments. Garlic cloves obtained from diseased plants were planted under controlled conditions, but the resulting plants did not develop rust. Fungicide trials were conducted for 3 years and showed that none of the currently registered materials gave satisfactory control. However, tebuconazole and azoxystrobin provided good protection against rust if sprayed at 10-day intervals. A variety trial of 34 garlic cultivars and selections was planted, inoculated, and evaluated for resistance to rust. Although there was variability in rust severity among the selections, acceptable levels of resistance were not observed in any cultivar.

Expression of Adult Resistance to Stripe Rust at Different Growth Stages of Wheat

Stripe, or yellow, rust (caused by Puccinia striiformis is a common disease of wheat in cool, humid climates. Genes that confer adult resistance to stripe rust are known to be present in high-yielding spring wheats (Triticum aestivum). However, it is not known when in the growth of the plant adult resistance is first expressed. The objectives of the study were to evaluate the expression of adult resistances at various growth stages in the greenhouse, and to assess the effect of such resistances on stripe rust development in the field. Eight wheat cultivars known to carry different levels of adult resistance and three susceptible cultivars were evaluated for resistance in the greenhouse at six growth stages (from seedling to anthesis), using a Mexican race of P. striiformis. Resistance was measured by infection type (IT) and latent period (LP). The cultivars were also evaluated in the field using the same race to determine disease progress. In all tests, Morocco was the most susceptible cultivar (IT 7 to 9, LP 11 to 13 days), followed by Avocet S (IT 6 to 9, LP 12 to 15 days) and Jupateco 73S (IT 6 to 9, LP 12 to 17 days). Seedling IT and LP for cultivars with adult resistance were similar to those of the susceptible cultivars (IT 6 to 8, LP 12 to 15 days). However, as plants grew, resistance increased and was expressed as lower IT and longer LP. The changes in IT displayed by HD2258 and PBW65 were the greatest; intermediate to low IT (2 to 3) were seen as early as the completion of tillering and changed to immunity (IT 0) at anthesis. Other cultivars with adult resistance, viz., Mexico 82, Pavon 76, Jupateco 73R, Apache 81, Anahuac 75 and Ciano 79, generally showed intermediate to moderately susceptible responses (IT 4 to 6) at growth stages later than tillering. The IT and LP displayed at anthesis by resistant cultivars were lowest and highest, respectively, indicating that adult resistance was best expressed at this growth stage. A strong negative rank correlation (r = -0.939, P < 0.01) between IT and LP at anthesis suggested that lower ITs of the cultivars were generally associated with longer LP. In the field study, HD2258 and PBW65 were highly resistant (relative AUDPC less than or equal to 5% of Morocco). Pavon 76 and Mexico 82 had acceptable resistance levels (relative AUDPC less than or equal to 20%), whereas other cultivars displayed moderate resistance levels (relative AUDPC 30 to 52%).

Association between dwarfing genes ?Rht1? and ?Rht2? and resistance toSeptoria tritici Blotch in winter wheat (Triticum aestivum L. em Thell)

Differences in levels of resistance toSeptoria tritici blotch were observed in plants with a specific height-reducing gene. When the gene 'Rht 2' was present either as an isoline or in the progeny, a higher degree of resistance was found. The most susceptible plants were observed in populations carrying the 'Rht 1' gene. Associations, as determined by phenotypic correlations, were detected betweenSeptoria tritici blotch and tall stature, late heading, and maturity. Plants having short stature, early heading, early maturity, and acceptable levels of resistance were identified in the F2 population whenRht 2 was present. Results of this study indicated that wheat breeders must select the appropriate dwarfing source that may confer resistance and grow large F2 populations, in order to increase the probability of obtaining desired genotypes.

Cultural Management of Dectes texanus (Coleoptera: Cerambycidae) in Sunflower

Larvae of Dectes texanus LeConte may cause serious losses in sunflower-seed production in the southern Great Plains by their burrowing in and internal girdling of stalks. Planting sunflower before mid-April or after late May at Bushland, Tex., significantly reduced stalk infestation by D. texanus larvae. A single disk or sweep tillage of sunflower stubble in October or January caused up to 73.5 and 39.7% mortality of overwintering larvae, respectively. Overwintering larvae began pupating in late May 1982 and mid-June 1983, with subsequent adult emergence beginning from mid- to late June. Commercial varieties and hybrids of sunflower and their F1 progeny from interspecific crosses with wild Helianthus species did not have acceptable levels of resistance to D. texanus larvae. Perennial species of Helianthus have a high level of resistance against stalk injury by larvae of D. texanus .

Reaction of Permutations of Maize Double Crosses to Leaf Feeding of European Corn Borers1

We tested the 3 permutations of 12 double‐cross hybrids plus all possible single crosses among 8 inbred lines for their reaction to first‐brood infestation by European corn borers. Double crosses with three or more resistant lines in their pedigree had a high level of resistance. Double crosses containing two highly resistant lines had an acceptable level of resistance. The differences which occurred in double‐cross permutations were primarily in hybrids composed of two resistant and two susceptible inbreds. However, the differences among permutations were small as compared to the total difference between resistant and susceptible plants. Differences between observed and predicted values of some permutations indicated that some type(s) of epistatic gene action was important in the expression of corn borer resistance.