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Wheat (Triticum aestivum L.) is one of the world's most important cereal crop in terms of cultivated area and quantity of grain produced. It is the most communal staple food in Pakistan, followed by rice and maize. Wheat is susceptible to a wide range of biotic and abiotic stressors, which can lead to severe yield reductions. Rusts are economically the most significant biotic factor of wheat crop. Leaf rust, commonly known as brown rust, is a severe wheat disease in Pakistan that results in production losses ranging from 10% to 40%. In the present study, the experiment was conducted in MNS-University of agriculture Multan, in which screening of wheat breeding lines against the natural inoculum of brown rust and the relationship of leaf rust with different environmental parameters was done in two years of data. The disease severity (DS), Coefficient of infection (CI) and average coefficient of infection (ACI) was recorded by using Modified Cobb's scale. During 2020-2021, among 100 breeding lines, 16 breeding lines revealed an immune response, 14 exhibited moderately resistant response, 5 showed a susceptible response and the remaining were moderately resistant-moderately susceptible response. In season 2021-22, 19 breeding lines were immune, 19 showed a moderately resistant response, 4 breeding lines were susceptible and the remaining were moderately resistant-moderately susceptible. Correlation clearly demonstrated the response of disease development to environmental factors. Maximum temperature, minimum temperature, wind speed and sunshine hours showed a positive relationship with leaf rust severity while a negative relationship was evident in relative humidity and disease severity during both year study. This study provided evidence that there is a strong relationship between environmental factors and leaf rust severity. The environmental conditions were not ideal during the early stage of the host plant that help them to withstand the building inoculum during March-April. Therefore, the breeding lines exhibiting immune and moderately resistant response could be utilized in future breeding programs to develop leaf rust resistant varieties/cultivars to combat this menace. [ABSTRACT FROM AUTHOR]

The aim of the work was to determine the role of bacteria to mitigate the effect of fluoride on the growth, gas exchange characteristics, and productivity of the two wheat varieties (Galaxy-13, Chakwal-50). Experiment was conducted in the Botanical Garden (University of the Punjab, Lahore Pakistan) according to the Design Expert software 11. Four concentrations of NaF (0 ppm, 150 ppm, 250 ppm, and 350 ppm) and three bacterial strains (ss5a, ss5b, and ss10a) were used. Growth parameters, gas exchange characteristics, fresh and dry weight of root and shoot, and productivity were measured. The results observed were less harmful in case of plants treated in combination with NaF+bacteria as compared to plants treated with NaF alone. Fluoride affected various parameters, chlorosis, leaf tip burn, leaf necrosis, growth, and productivity of the wheat plants. Galaxy-13 was least influenced by F compared to the Chakwal-50 variety. It was concluded that growth was increased with the application of beneficial fluoride resistant bacteria and proved helpful in minimizing the harmful effects of fluoride salt on wheat varieties. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) is a staple food for a significant portion of the world's population including Pakistan. Among all limiting biotic and abiotic factors, wheat rusts pose a substantial danger to production worldwide and can result in yield losses of over 90% in susceptible varieties or during epidemics. Yellow rust (Puccinia striiformis f. sp. tritici), one of several types of wheat rust, is particularly dangerous to wheat production in Pakistan and cause disease on 70% cultivated area of wheat. Keeping in view the devastating nature of yellow rust pathogen, two-year study 2020-2021 and 2021-2022 was conducted in order to screen out wheat breeding lines against yellow rust followed by its relationship with the environmental variables. In this study, one hundred wheat breeding lines were cultivated in the research area of MNS-University of Agriculture Multan and disease was observed in the months of January-April during 2020-21 and 2021-22. Very low level of disease severity (DS) and area under disease progress curve (AUDPC) recorded in all the breeding lines. Epidemiological variables play an important role in the disease progression. Hence, out of hundred breeding lines screened in 2020-2021, 88 breeding lines were supposed to be immune to all naturally occurring race(s) of yellow rust and 12 lines were categorized as moderately resistant to moderately susceptible. Similarly, 92 breeding lines were found immune and 8 showed moderately resistant to moderately susceptible response out of 100 breeding lines during 2021-2022. The findings showed that a high proportion of wheat breeding lines showed no response towards the disease and supposed to be immune. The results from the correlation and regression analysis showed that there was a positive correlation between the maximum, minimum temperature with yellow rust severity (%). While, there was a negative correlation of humidity during 2020-2021 and positive during 2021-2022. Sunshine hours showed the positive relationship with the yellow rust severity (%) during 2020-2021 and negative during 2021-2022. Current study revealed that breeding lines and pathogen were present, which was responsible for the disease in few breeding lines, while epidemiological factors were non-favorable for the disease to develop and progress at large scale. The findings of the current research clearly showed the importance of epidemiological factor which leads toward less disease development. The analysis of natural conditions with yellow rust helps to predict yellow rust outbreak and appropriate management strategies. [ABSTRACT FROM AUTHOR]