AP2 transcription factors are a large class of transcription factors that play important roles in plant signaling, growth and development, and stress responses. To explore the molecular characteristics of AP2 transcription factors in wild emmer wheat, based on the genomic information of wild emmer wheat, AP2 gene family members were identified using Blast and Hmmer. The identified members were analyzed for protein physicochemical properties, subcellular localization, phylogenetic tree, conserved domains, gene expansion, cis-acting elements, codon usage bias, expression patterns, and genetic diversity. The results showed that a total of 265 AP2 genes were identified in wild emmer wheat, mainly located in the nucleus and chloroplasts. According to phylogenetic analysis, they were grouped into 3 subfamilies, showing both conservation and diversity in conserved domains and gene structures between subfamilies. Predictions of cis-acting elements indicated that AP2 contains multiple elements related to growth, development and abiotic stress. Analysis of codon usage bias revealed that the codon bias of AP2 genes may be subject to selective pressure. The expression pattern analysis of AP2 genes in tissues and under salt stress suggested subfunctionalization within the family and their important role in salt stress response. Analysis of nucleotide diversity and population differentiation indices in different wheat populations indicated that some members of the AP2 gene family exhibit high genetic diversity in wild emmer wheat.

To study the effects of different cultivation modes and ecological conditions on the grain quality of weak gluten wheat, 8 Yangmai series and Ningmai series weak gluten wheat varieties and 2 medium gluten wheat varieties were used as materials to analyze the stability and differences of grain bulk weight, protein content, and starch content of weak gluten wheat under different cultivation modes and ecological conditions. The results showed that the quality of wheat grains is not only controlled by genetic factors of the variety, but also influenced by cultivation modes and ecological conditions. Under different ecological conditions, the high-quality cultivation mode of weak gluten wheat was based on a basic seedling of 2.40×10⁶plants·hm^-2, pure nitrogen of 180 kg·hm^-2, and phosphorus and potassium fertilizers mainly based on basal and seedling fertilizer. The nitrogen fertilizer was based on basal fertilizer:seedling fertilizer:jointing fertilizer (before 3.5 leaves)=7∶1∶2. Under this cultivation mode, weak gluten wheat showed low protein content, good grain bulk weight, and high starch quality. Medium-gluten varieties Yangmai 25 and Yangmai 28 could also meet the requirements of high-quality weak gluten. The high-yield cultivation mode was based on a basic seedling rate of 1.80×10⁶plants·hm^-2, with pure nitrogen of 240 kg·hm^-2. Phosphorus and potassium fertilizers were mainly based on basal and seedling fertilizer, and nitrogen fertilizer was based on basal fertilizer: seedling fertilizer: jointing and booting fertilizer=5∶2∶3. The tested varieties showed high protein content in their grains under this cultivation mode, and most varieties can not meet the standards of weak gluten wheat. To ensure the quality of weak gluten wheat, suitable varieties should be selected, and the first cultivation mode should be adopted based on conventional field cultivation measures, and appropriate adjustments should be made according to the local climate and ecological conditions of the year.

Wheat grain weight is one of the important yield components and a quantitative trait influenced by genetic factors. To clarify the distribution of grain weight genes in Xinjiang wheat and the applicability of related molecular markers in breeding, 253 Xinjiang winter wheat varieties were used as experimental materials. KASP (competitive allele specific PCR) markers were used for genotype detection, and association analysis was conducted with breeding selection traits such as plant height, spike length, grain number per spike, thousand-grain weight, grain length, and grain width in two years. The results showed that the distribution frequencies of excellent alleles TaSus1-7A-Hap1, TaCwi-A1b, TaTGW-7Aa, TaGS5-A1b, TaGS2-A1b, TaGS-D1a, TaSus2-2B-HapH, TaTGW6-A1a, TaGW2-6B-Hap3, and TaSus2-2A-HapA in the test materials were 100%, 100%, 84.98%, 56.92%, 51.78%, 39.13%, 33.20%, 11.07%, 3.16%, and 1.58%, respectively. There were 118 combinations of the 14 alleles in the test materials; GS5-2334-SNP, TaGS2-A1-239IND2, TGW7-986-SNP, and GW2-6B-721SNP can be applied for marker assisted selection of wheat grain weight. The detected linkage genes are significantly correlated with one or more breeding traits. The GS5-2334-SNP linkage gene TaGS5-A1 has 36.65% effect on grain width, followed by 27.76% effect on thousand-grain weight. The GS5-2334-SNP linkage gene TaGS5-A1 has an effect on plant height and grain weight per ear; the GW2-6B-721SNP linkage genes TaGW2-6B and TGW7-986-SNP linkage genes TaTGW7 have an effect on grain length; the Sus2-20-20SNP linkage gene TaSus2-2A has an effect on grain weight per ear, thousand-grain weight, and grain width, and their effects all reach over 10%. This study can lay the foundation for molecular marker assisted breeding for wheat.

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 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.

In order to explore the effects of late sowing on plant traits, grain yield and quality of strong gluten wheat in eastern Hebei Province, two strong gluten wheat varieties Jinnong 7 and Zhongmai 998 were selected as experimental materials. Five sowing dates suah as normal sowing dat (D1), late sowing 7 d (D2), late sowing 14 d (D3), late sowing 21 d (D4) and late sowing 28 d (D5) were set up. Effects of dry matter accumulation and transport, grain yield and flour processing quality of strong gluten wheat late sowing were analyzed, and the relationship between accumulated temperature before winter and wheat yield and quality traits was analyzed. The results showed that late sowing increased flag leaf area and tiller earing rate, reduced the plant height, dry matter accumulation and transport to grains leading to decreased the spike number per hectare, 1 000-grain weight and yield of strong gluten wheat. Jinnong 7 and Zhongmai 998 showed significantly decreased yield under D2 and D3, respectively. With the delay of sowing date, the grain protein content, wet gluten content, stability time and maximum tensile resistance of flour showed a trend of increasing first and then decreasing. The protein content was the largest at D3 and D4, wet gluten content and gluten index of the two varieties were the largest at D3, the stability time and tensile area were the largest at D4, and the maximum tensile resistance was the largest at D4 and D2, respectively. Correlation analysis showed that the accumulated temperature before winter was significantly positively correlated with plant height and spike number of strong gluten wheat at 0.01 level, significantly positively correlated with 1 000-grain weight and yield at 0.05 level, but significantly negatively correlated with flag leaf area, gluten index and stability time at 0.01 or 0.05 levels. Under the conditions of this experiment, the best sowing date for Jinnong 7 to achieve high yield and high quality is normal sowing date, and the best sowing date for Zhongmai 998 is late sowing 7 d. In summary, late sowing is not conducive to high yield of strong gluten wheat, but appropriately delaying sowing date can increase the content of protein and wet gluten in wheat grains, thereby improving nutrition and processing quality.

The traits of Yr5, Yr9 (1B/1R), and Yr18 genes play an important role in wheat breeding in China, and the molecular markers STS9/10 of Yr5, AF1/4, D15, 20H of Yr9 (1B/1R) and csLV34, cssfr1~cssfr5 of Yr18 were effectively tested by applying near isogenic lines under background of Avocet S and lines with known Yr genes. The results showed that the specific molecular markers of Yr5 gene STS9/10, Yr9 (1B/1R) gene AF1/4, D15 and 20H could accurately identify the corresponding resistance genes in different genetic background materials. Yr18 gene molecular marker cssfr2 could accurately detect the materials not-carrying Yr18, and detect allelic variation of Yr18 in Avocet S*6/Yr5, Avocet S*6/Yr24, and Avocet S*6/Yr27. There fore, the linkage marker STS9/10 of Yr5 gene, the molecular markers AF1/4, D15 and 20H of Yr9 (1B/1R) gene can effectively detect the target gene, and the combination of several molecular markers of Yr18 gene not only effectively detected the target gene but also identified the allelic variation of this site.

Wheat is one of the primary staple crops for human beings, and wheat grain is an important raw materials for green organic food and nutritional health food. Endosperm tissue of wheat grain can be divided into endosperm transport cells and storage cells; the former is the key channel for nutrients to enter endosperm and embryo, and the latter is the bulk for grain nutrient accumulation. The developmental state of both is closely related to grain nutritional quality. In this paper, the developmental regularity and their functional mechanisms of endosperm transport cells and storage cells were reviewed, and the endosperm development and its relationship with nutrient quality in wheat grain were summarized, providing the theoretical basis for the cultivation of high yield and quality wheat varieties.

To determine the suitable sowing date for winter wheat in Anhui Province, the spatio-temporal variation characteristics of accumulated temperature from October to December were analyzed using observation data from 50 meteorological stations distributed in the wheat areas of Huaibei, Jianghuai, and along the Yangtze River from 1971 to 2021. Based on accumulated temperature requirements for different pre-winter leaf ages, the sowing dates for winter wheat in the first 30 years (1971-2000) and the recent 21 years (2001-2021) were analyzed corresponding to different leaf ages. The results showed that from 1971 to 2021, the monthly and total accumulated temperature from October to December in Anhui Province and its wheat areas showed a significant linear increase trend. The increase rates of monthly and total accumulated temperature in Anhui Province from October to December were 8.6, 9.6, 7.8, and 26.1 ℃ per decade, respectively. The increase rate of monthly accumulated temperature in Anhui Province and its wheat areas from October to December showed a pattern ranking as November>October>December. The increase rate of accumalated temperature in the wheat area along the Yangtze River in December (6.5 ℃ per decade) was significantly lower than that in the Huaibei (8.4 ℃ per decade) and Jianghuai (8.3 ℃ per decade) wheat areas. The increase rate of total accumulated temperature from October to December in the Huaibei and Jianghuai wheat areas was 26.6 ℃ per decade, while the wheat area along the Yangtze River was slightly lower (24.9 ℃ per decade). When Anhui winter wheat grows to the same leaf age before winter, the sowing date in the past 21 years was generally delayed by 1-4 days compared to the first 30 years. The suitable sowing dates for wheat in the Huaibei, Jianghuai, and along the Yangtze River areas were delayed by an average of 2.61, 2.86, and 2.07 days in the past 21 years, compared to the first 30 years, respectively. The suitable sowing dates for semi-winter and weak winter varieties in the Huaibei wheat area in the past 21 years were October 16-21 and October 12-16, respectively. The suitable sowing dates for spring and semi-winter varieties in the Jianghuai wheat area are October 25-30 and October 21-25, respectively. The suitable sowing dates for spring wheat varieties in the wheat area along the Yangtze River are October 30-November 4.