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71.
ABSTRACT Development of 108 epidemics of Fusarium wilt of chickpea caused by Fusarium oxysporum f. sp. ciceris were studied on cvs. P-2245 and PV-61 in field microplots artificially infested with races 0 and 5 of F. oxysporum f. sp. ciceris in 1986 to 1989. Disease progression data were fitted to the Richards model using nonlinear regression. The shape parameter was influenced primarily by date of sowing and, to a lesser extent, by chick-pea cultivars and races of F. oxysporum f. sp. ciceris. Fusarium wilt reduced chickpea yield by decreasing both seed yield and seed weight. These effects were related to sowing date, chickpea cultivar, and virulence of the prevalent F. oxysporum f. sp. ciceris race. Regression models were developed to relate chickpea yield to Fusarium wilt disease intensity with the following independent variables: time to initial symptoms (t(is)), time to inflection point (t(ip)) of the disease intensity index (DII) progress curve, final DII (DII(final)), standardized area under DII progress curve (SAUDPC), and the Richards weighted mean absolute rate of disease progression (rho). Irrespective of the chickpea cultivar x pathogen race combination, the absolute and relative seed yields decreased primarily by delayed sowing. The relative seed yield increased with the delay in t(is) and t(ip) and decreased with increasing DII(final), SAUDPC, and rho. A response surface as developed in which seed yield loss decreased in a linear relationship with the delay in t(is) and increased exponentially with the increase of rho.  相似文献   
72.
The effect of buck genetic type and crossbreeding parameters on fertility and prolificacy were estimated using two rabbit sire lines and their reciprocal crosses. The relationship between the reproductive performance of inseminated multiparous does and several semen quality traits was also investigated. The semen characteristics evaluated were: pH (pH), mass and individual motility (MM, IM), percentage of viable spermatozoa (Vi), spermatozoa with normal apical ridge (NAR), normal spermatozoa (NSP), spermatozoa with morphological abnormalities of head (HAP), neck-midpiece (NAP), and tail (TAP), spermatozoa with the presence of proximal (PD) and distal (DD) cytoplasmic droplets.

Fertility was analysed as a continuous trait (kindling rate) or as a binary trait (success or failure of kindling). In the first case, the analysis was performed using GLM procedures of SAS v.8 according to a model that included the fixed factors of buck genetic type, number of ejaculates per pool and week of insemination. In the second case, fertility was analysed using GENMOD procedures of SAS v.8 according to a mixed model including the same fixed factors as before plus the physiological status of the does and the permanent random effect of female. Number of kits born alive and number of stillborn were analysed with MIXED procedures of SAS v.8 with the same model used for the analysis of fertility as a binary trait. Estimates of the estimable functions of crossbreeding genetic parameters of the lines were obtained from the solutions of the corresponding models by generalized least squares using GLM, GENMOD and MIXED procedures. Crossbreeding parameters were estimated according to the model of Dickerson. A linear regression was used to determine the relationship between fertility and litter size and the semen characteristics evaluated.

Significant differences in fertility were observed among buck genetic types, which were favourable to type R. Differences between lines in maternal genetic effects were relevant and favourable to type R for fertility. Individual heterosis was important but unfavourable for fertility.

A slight correlation was obtained between all semen quality traits and fertility and prolificacy. Two multiple models were found for fertility, including NAP, IM, NSP, buck genetic type and Vi in one model or NAR in other model. Individual motility had an important positive effect, while NAP had a small negative effect. When MM, TAP and buck genetic type were included in a multiple model for the number of kits born alive, both MM and TAP had significant small effects. Individual motility and DD appeared to be related to number of kits stillborn, but only DD had a significant although negligible effect.  相似文献   

73.
A complete diallel cross involving two rabbit sire lines (C and R) was carried out to estimate the crossbreeding genetic parameters of seminal traits. 2140 ejaculates from 153 males were analyzed. The traits studied were: presence of gel plugs (G), urine (U), and calcium carbonate deposits (CC), number of useful ejaculates (UE), pH, volume (V), mass and individual motility (Mm, Mi), useful Mi (UM), concentration (Cn), number of spermatozoa per ejaculate (TSE), percentage of viable spermatozoa (Vi), spermatozoa with normal apical ridge (NAR), normal spermatozoa (Nr), spermatozoa with morphological abnormalities of head (H), neck-midpiece (Nm), and tail (T), presence of proximal and distal cytoplasmic droplet (Dp, Dd).

Estimates of heterosis, direct and maternal genetic effects were obtained from the solutions of the mixed model. There were major differences in direct genetic effects between lines, which were favourable to line C for Cn and TSE, and unfavourable for CC, Nm and Dp. Smaller differences were also observed in Vi and NAR favourable to line R. Differences between lines with respect to the maternal genetic effects were relevant and favourable to line C for V and to line R for U, UM, Cn, TSE, Nm, Mi, and Mm. Individual heterosis was high for Dp and Dd.  相似文献   

74.
The aim of the study was to compare how different feeding levels affect the ovarian potential of follicular development and oocyte maturation in response to superovulatory treatment in native Mangalica (M, n = 17) compared with Landrace (L, n = 20) pigs. Gilts of both breeds were fed high-energy (HI-2.5 kg) or low-energy (LO - 1.25 kg) feed during oestrus synchronization (15 days of Regumate feeding) till the time of oocyte aspiration (Day 6 after Regumate). Follicular growth was stimulated by the administration of 1000 IU equiue choriou gonadotropiu (eCG) 24 h after Regumate treatment, and ovulation was induced by injection of 750 IU human choriou gonadotropiu (hCG) 80 h after eCG administration. Ultrasound (US) investigation was done three times (4-10 h before, and 40-44 and 72-74 h after eCG administration) for the observation of follicular development. Oocyte and follicular fluid (FF) were collected endoscopically 34 h after hCG injection. Cumulus-oocyte complexes were evaluated, their morphology determined, and thereafter fixed and stained for chromatin evaluation. Oocytes were classified as meiosis-resumed (germinal vesicle breakdown, diakinesis, metaphase I to anaphase I) or matured (telophase I and metaphase II). FF concentrations of oestradiol and progesterone were measured by validated radioimmunoassays. In L gilts, differences were observed between HI and LO in the number of preovulatory follicles (32.3 +/- 10.5 vs 17.1 +/- 12.3, p < 0.05), but not in M (25.3 +/- 2.9 vs 28.8 +/- 7.3, p > 0.05). Initial follicular growth was not affected by feeding levels; however, preovulatory follicle size was larger in M (7.1 +/- 0.9 and 6.9 +/- 1.1 mm vs 5.7 +/- 0.7 and 5.5 +/- 0.8 mm; p < 0.05). No differences were obtained with relation to mature chromatin configuration in both breeds (L gilts: HI - 70% and LO-67% vs M gilts: HI - 67% and LO - 63%). A twofold higher oestradiol concentration was detected in FF of HI-M and LO-M (29.6 +/- 6.8 and 30.9 +/- 10.3 ng/ml respectively) compared with that of L (16.9 +/- 9.7 and 17.9 +/- 3.6 ng/ml, respectively; p < 0.05). The mean FF progesterone level was nearly fivefold higher in M (2020.4 +/- 1056 and 1512.2 +/- 1121.8 ng/ml) compared with L (386.2 +/- 113.7 and 298.8 +/- 125.9 ng/ml, p < 0.05). The results indicate an influence of the feeding of altered energy on the number of recruitable preovulatory follicles in modern Landrace but not in native Mangalica breed. Moreover, the follicular steroid hormone milieu differs between Landrace and Mangalica gilts but not depending on feeding levels. Oocyte maturation was not affected by diet.  相似文献   
75.
Mucus plays an important role in gut health by favouring colonisation resistance. The aim of this study was to quantify the impact of fibre and protein on mucin recovery in ileal digesta and on goblet cell histochemistry in the proximal colon. A control diet with highly digestible protein and low fibre and three complex diets containing indigestible protein associated with low, soluble or insoluble fibre sources were tested for 14 days in piglets weaned at 28 days of age. Mucin concentration was determined by ethanol precipitation. Goblet cell subtypes in colonic crypts were analysed by histochemistry. The ileal mucin output was higher with the complex diets than with the control diet (31.6 on average vs 21.7 g/kg DM intake). Increases observed with the low and soluble fibre diets were similar (34 g/kg DM intake). This suggests a limited effect of soluble fibre in presence of indigestible protein. Surprisingly, the observed increase was lower with insoluble fibre (27.2 g/kg DM intake). DM and N output and digestibility were not affected by the diets, but a linear relationship was found between DM and mucin output. In proximal colon, crypt depth, goblet cell numbers per crypt and glycosylation subtypes were not affected by the diet suggesting no change in the capacity of mucus to protect the gut. To conclude, introducing highly indigestible protein in the diet increased ileal mucin output, without effects of these factors on crypt goblet cell patterns in the proximal colon. Introducing fibre in a diet containing highly indigestible protein had a marginal effect.  相似文献   
76.
The potential negative environmental impact of manure and biological waste (BW) can be minimised at a profit by recycling plant nutrients in the food chain. Current large-scale livestock production, epizootic diseases and increasing globalisation increase the need for biosecurity, to minimise the risk of disease transmission to the food chain. Arable use of manure and BW can inadvertently spread infectious diseases; opinion differs concerning the risk levels. To obtain general acceptance for arable use, a hygienically safe end-product is needed. This paper provides a detailed discussion of treatment alternatives for co-treatment, i.e., mixture before treatment of manure and BW. Composting, anaerobic digestion and ammonia treatment are the three options given. A decision support tool is also presented and discussed. Suitable treatment methods must combine biosecurity aspects with environmental, economic and nutrient recycling aspects to create a beneficial whole-farm approach.  相似文献   
77.
The effect of different types of fibre on the intestinal digesta and microbial diversity was evaluated in growing pigs. The animals were fed during forty-two days with one of four experimental diets including a control group, a diet enriched with resistant starch type I, by coarse ground corn, and other two diets containing sugar beet pulp (8%) and wheat bran (10%) (as sources of soluble and insoluble non-starch polysaccharides respectively). Body weight (BW) and average daily feed intake (ADFI) were assessed at day 7, 21 and 42. Luminal samples of digesta from proximal colon were collected to analyse water retention capacity (WRC), concentration of short-chain fatty acids (SCFA) and the microbial diversity. Overall, animals fed with higher amounts of non-digestible carbohydrates had lower ADFI and BW. Sugar beet pulp provoked an increase of WRC, a higher concentration of SCFA, and a more stable microbial diversity throughout the experimental period. On the other hand, animals fed with wheat bran presented a lower bacterial diversity.  相似文献   
78.
A common female founder individual of the Portuguese horse breeds Sorraia and Lusitano was found while conducting research on the variation of the Lusitano mitochondrial DNA lineages in relation to studbook information. We obtained 416‐bp control region sequences from 16 descendents of a female Sorraia founder (Pomba) still represented in the living population of the Lusitano, according to the most recent edition of this breed's studbook. The same haplotype was found for all analysed samples and belongs to the haplogroup described by several authors as having predominantly Iberian, South American and North African haplotypes bringing new insights on the relationship between the Sorraia and the other Iberian breeds. This work illustrates how weak the boundary of breed establishment can be, especially at the same geographical region. Using the same founders in different breeds is surely one of the explanations to frequently shared haplotypes among recent breeds, resulting in a lack of consistency between mtDNA sequences and breeds and/or geographical regions.  相似文献   
79.
The trifluralin is an agent that promotes a cellular damage due to its direct action on the microtubules. This action leads to a decontrol in the cellular division, bringing about polyploid cells. In this work, we show the evidences that the exceeding genetical material of theses polyploidizated cells tends to be eliminated from the nucleus in the form of micronucleus. Our analyses prove this fact, both by the presence of a number of cells carrying micronucleus, and by the evidences of the elimination of the exceeding material itself, after exposition of the Allium cepa root tips tested with several concentration of trifluralin herbicide. It was noticed that the residual concentration induced a number of polyploid cells, micronuclei and mini cells. Inferences about the implications of the elimination of genetic material from micronuclei, such as cell viability and apoptosis, are also presented.  相似文献   
80.
Vegetative growth, yield, and fruit quality of ‘Fallglo’ and ‘Sunburst’ mandarins on ‘Rangpur’ lime, ‘Swingle’ citrumelo, ‘Orlando’ tangelo, and ‘Cleopatra’ mandarin were evaluated under subtropical climate of Northern São Paulo State, Brazil, from 2000 through 2006 harvest seasons. ‘Fallglo’ mandarin trees had the highest cumulative yield on ‘Rangpur’ lime, and the smallest on ‘Swingle’ citrumelo and ‘Orlando’ tangelo. Plants of this cultivar had the highest yield efficiency on ‘Rangpur’ lime, and the lowest on ‘Orlando’ tangelo. ‘Sunburst’ mandarin trees began to bear fruits later than ‘Fallglo’ mandarin trees, with no differences in yield induced by the rootstocks. ‘Cleopatra’ mandarin induced the most vigorous growth in ‘Fallglo’ mandarin as compared to plants on ‘Swingle’ citrumelo. On the other hand, the largest trees of ‘Sunburst’ mandarin were registered on ‘Orlando’ tangelo, and the smallest on ‘Rangpur’ lime. ‘Sunburst’ mandarin had higher alternate bearing than ‘Fallglo’ regardless the rootstock. Fruit weight and juice content were not affected by the rootstock. These two mandarin scion cultivars may be considered adequate alternatives to produce good fruit quality for the fresh fruit market. ‘Cleopatra’ mandarin and ‘Rangpur lime are suitable rootstocks for ‘Fallglo’ mandarin, whereas all rootstocks evaluated are adequate for ‘Sunburst’ mandarin.  相似文献   
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