The rust fungi especially emergence of new rust races has serious threat to global wheat production. This is mainly due to the widespread use of race-specific seedling resistance genes and evolution of new virulence races like Yr9, Yr27, and Sr31. Several quantitative disease resistance (QDR) or durable resistance genes i.e. Lr34/Yr18/Pm38/Sr57, Lr46/Yr29/Pm39/Sr58, Lr67/Yr46, Lr68 providing resistance to rust diseases at either high or low temperatures have been identified. But, changing climatic conditions affect the level of resistance in cultivars, as at high temperature Lr34/Yr18 genes which confer durable resistance in wheat become less effective and at low temperature it provides high resistance. While in contrast, yellow rust resistance genes; Yr36 and Yr39 confer resistance at high temperature and later growth stages. This review provides a detailed discussion on, the different aspects of climate change that how it affect host resistance and pathogenic variability and its sustainable control by developing cultivars with high level durable resistance.
Ostriches are the biggest ratite in the world. Their wild changing behaviour helps us to consider them as domestic birds. Ostriches can reach adult height 6-10 feet tall in between 1.5 to 2 years of age and their head may reach 1.8-2.75m above the ground due to large legs. These largest vertebrate only run in case of any danger and can run at a speed of 65-70 kilometer per hour. Presently there are four subspecies of ostriches which are limited to Africa. Ostriches can be reared on short grass plains and semi-arid desert areas. Meat of ostriches is very healthy for humans' consumption. Ostrich birds produce red meat that is similar to deer meat or beef and the hide makes fine leather products. Frequency of mating may be low in confined environment. Mostly breeders are kept in group of trio (1:2); one male for two females. Ostriches can live on any cattle fodder; however during early six months of life they need special feeds for better growth. Ostriches may gain 1Kg body weight with only 3Kg food, unlike cattle which gain 1Kg body mass with 20kg fodder. Ostrich may reach sexual maturity at about two to three years of age and lay 100eggs per season. Ostrich farming is now being done in the globe. Ostrich in Pakistan are now announced as a farm bird of commercial interest which is new turn in poultry industry of Pakistan.
Epidemics of leaf, stripe and stem rusts on wheat have induced significant losses in the past during the early nineteenth century and have destroying role in reducing product yield bringing about socioeconomic variability worldwide. The old tall varieties with qualitative resistance couldn't continue for longer period because of the advancement of new virulent pathogen races. But varieties like Yaqui-50, Lyalpur-73, and Lerma Rojo-64 were released during early period of green revolution, still linked with durable resistance to stripe, leaf and stem rust. Advancement of new rust races like virulence's Yr27 and Yr9 followed by the appearance of Ug99 and its mutants lead the breeders to review their breeding plan. Breeders are presently relying upon to gather minor genes and their use in grouping with major genes to develop rust resistance in wheat varieties. The minor genes, Lr46/Yr29, Lr34/Yr18, Sr2/Yr30, are being broken in wheat breeding at CIMMYT and different region. The germplasm with this kind of resistance have shown existence stability over space and time. At Ayub Agriculture Research Institute, Faisalabad the home of green revolution in Pakistan, this approach has been established since1994-95. The durable resistance assortments were crossed in a top cross/back cross technique and the segregating populations were improved by adopting mass strategy, which brought about the advancement of material having preferred yield and rust resistance over the pre-exiting assortments (e.g., Inqlab-91, MH-97). Five varieties, Shafaq-06, Lasani-08, AARI-11, Millat-11 and Galaxy-13 from these crosses have been approved for general cultivation. Essentially, the material developed and circulated by CIMMYT, Mexico having this sort of resistance is being worldwide adopted. The simple sequence repeat markers (SSR) for above mentioned durable genes are accessible and can be used in early selection of superior varieties.
Two fungicides, Aliette and ThiovitJet @ 0.15%, containing Aluminum tris (O-ethyl phosphonate) and sulphur compounds, respectively; two plant extracts, Melia azedarach and Azadirachta indica @ 8% and one biocontrol agent, Trichoderma harzianum @ 107 conidia ml-1 were investigated against ascochyta blight of chickpea under field conditions. Treatments were evaluated on three varieties susceptible to chickpea blight. Field trial revealed that Aliette and ThiovitJet significantly decreased disease severity to 17 and 23% respectively, followed by M. azedarach and A. indica which decreased severity to 50 and 56% respectively, compared to control with 75% disease severity. T. harzianum, with a severity of 63%, was significantly less effective than fungicides and both plant extracts in controlling blight disease. The current research revealed that systemic and sulphur containing fungicides, both plant extracts and the biocontrol agent have the potential to control ascochyta blight of chickpea.
A comprehensive germplasm screening study of 855 wheat advanced lines was conducted at Wheat Research Institute, Ayub Agricultural Research Institute Faisalabad to identify new sources of leaf rust resistance during crop seasons 2015-2017. In primary evaluation, 112 advanced lines were selected having high phenotypic uniformity for further testing at wheat research Institute Faisalabad, a hotspot for leaf rust. The second round of evaluation exhibited 54 lines having durable type resistance against leaf rust. Avirulence to virulence formula showed that 7 Lr genes remained most effective at all four locations. Epidemiological factors indicated great influence on the progress of leaf rust disease development. Maximum lines showed statistically significant correlation with all environmental conditions. A positive linear relationship was observed between minimum and maximum temperature, relative humidity, rainfall and wind speed. It was concluded that resistant wheat advanced lines and Lr genes identified under natural environmental conditions can be an excellent source to be employed for breeding resistance into the background of high yielding wheat cultivars through molecular or conventional breeding technique, and are expected to contribute toward food security at national and global levels.
Wheat leaf rust (Puccinia recondite f. sp. tritici) is amongst major wheat diseases occurring in all wheat growing areas of Pakistan. Losses due to the infection by P. recondite f. sp. Tritici have lowered the wheat production potentially in previous years in Pakistan. This problem can be avoided by incorporating resistance against disease in wheat. In the present study eight genotypes/lines were screened and correlated with epidemiological factors i.e. temperature, relative humidity, rainfall and wind speed. The overall results revealed that among all these lines, four genotypes/lines i.e. A-24, A-20, K-11 and A-25 were susceptible to leaf rust of wheat, while the rest of four lines/genotypes i.e. A-09, A-17, A-08 and A-29 were moderately susceptible to this disease. No line/genotype showed resistant, moderately resistant or immune response to leaf rust of wheat. Correlation showed clear response of disease development to environmental factors. Maximum temperature of the disease severity was 23.8-27.15 o C. Similarly, the range of minimum temperature at which disease severity recorded maximum was 16-18 o C. The ranges of relative humidity, rainfall and wind speed on which disease severity was maximum were 60-64%, 8-22.50 mm and 11.8-12.98 Km/h, respectively. The study showed that environmental conditions of Sargodha significantly affected disease development of leaf rust of wheat.
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