In order to explore the climate change characteristics at different growth stages of drought-alkali-resistant wheat in Hebei and their impact on wheat yield, the meteorological observation data and yield data from the main production areas of drought-alkali-resistant wheat from 2009 to 2022 were collected, and various methods, including quartiles and climate slopes, were employed to analyze the climate characteristics and trends at different growth stages of drought-alkali-resistant wheat. Subsequently, the second-order curve method was used to separate meteorological yield, and the grey correlation degree method was applied for a dual quantitative analysis of the impact of meteorological factors on wheat yield during different growth stages. The results were as follows: (1) At each growth stage of drought-alkali-resistant wheat, there were clear distribution patterns for average temperature, maximum temperature, minimum temperature, and sunshine hours. Precipitation was the most variable meteorological factor in the growth and development process of drought-alkali-resistant wheat. (2) There were significant differences in the trends of various meteorological factors at different growth stages of drought-alkali-resistant wheat. (3) Monofactor quantification revealed that precipitation at sowing stage, tillering stage, overwintering stage and heading stage, sunshine hours at seeding stage and grain filling stage, average temperature at reviving, minimum temperature at jointing stage had the greatest impact on the meteorological yield of drought-alkali-resistant wheat. (4)Dual quantification indicated that the top five meteorological factors affecting the meteorological yield of drought-alkali-resistant wheat, ranked as precipitation at tillering stage, precipitation at overwintering stage, minimum temperature at tillering stage, minimum temperature at jointing stage, and precipitation at heading stage. Therefore, in order to promote wheat growth and high yield in drought-alkali-resistant wheat planting areas in Hebei, some field water management measures such as water conservation and irrigation should be used according to the precipitation change during wheat growth period, and the low temperature impact on wheat should attact more attention at tillering and jointing stages.

The middle and lower reaches of Yangtze River is the largest production belt of weak-gluten wheat in China. Due to the humid and rainy weather in the middle and late period of wheat growth, Fusarium head blight (FHB) and powdery mildew (PM) occurre frequently and seriously, and FHB led to the accumulation of DON toxin in pathogen-infected grains. Wheat yellow mosaic virus (WYMV) often happens after a cold winter. These disasters threaten grain yield and food security. Yangmai 15 is an elite weak-gluten and high-yield cultivar bred at the beginning of 21 century, but its comprehensive resistance is weak. To keep the advantages of Yangmai 15 and improve disease resistance, a backcross population was constructed with Yangmai 15 as the recurrent parent, and 92R137(a soft-grain cultivar with high resistances to PM and WYMV) and Ningmai 9(a soft-grain wheat cultivar conferring moderate resistance to FHB) as the donor parents. In lower generations, molecular markers were used to select plants pyramiding PM resistance gene Pm21 and WYMV resistance QTL QYm.nau-2D. In high generations, FHB resistance was evaluated and the key quality indices were tested together with grain yield. Finally, a new weak-gluten and high-yield wheat line Yang 18465 conferring resistance to FHB, PM and WYMV, was bred and introduced to the national wheat regional test in the middle and lower reaches of Yangtze River. The breeding procedures of Yang 18465 will provide a useful reference for the breeding of similar varieties.

In order to explore the effects and mechanism of climate warming on the growth and yield of strong-gluten and high-quality wheat variety, Jimai 229 was used as the experimental material, and the effects of whole-growth warming on the growth and development, flag leaf senescence characteristics, and yield of Jimai 229 were investigated with the wheat grown at natural temperature in the field as control. The results showed that warming during the whole growth period increased the number of tillers, plant height, leaf area of the top leaf, SPAD value and above ground dry matter accumulation of Jimai 229 during the vegetative growth stage. However, it accelerated the decrease rate of leaf area and SPAD value of flag leaves after anthesis, and reduced dry matter translocation to spike. Warming had little effect on SOD, POD and CAT activities of flag leaves of Jimai 229 at the booting stage and anthesis stages, and MDA content and Pro content in flag leaves were at low level, which resulted in significant increase in the SOD activity of flag leaves, and reduced the POD and CAT activities to different degrees after anthesis, leading to the increase in MDA and Pro contents and the relative electrolytic leakage. Warming reduced the number of spikes and the thousand-grain weight of Jimai 229 by 20.3% and 10.0%, and the yield by 24.1%, with insignificant effect on the number of grains per spike. In conclusion, warming during the whole growth period can promote the vegetative growth of Jimai 229, which is not conductive to the photosynthesis and antioxidant action of wheat flag leaves during the reproductive growth stage, leading to accelerated senescence of the flag leaves and lower yield.