Search Results (79)

Unpollinated ovary culture is an effective approach for generating haploid and doubled haploid lines, but its application in Chinese chive (Allium tuberosum) breeding has been constrained by strong genotype dependence and low regeneration efficiency. This study evaluated an efficient gynogenesis induction system and analyzed transcriptomic changes associated with embryogenesis. Among 20 evaluated genotypes, the commercial cultivar ‘21-CJ46’ showed the strongest response. The optimized induction conditions utilized ovaries collected 1 day before anthesis, cultured on Murashige and Skoog medium supplemented with 90 g/L sucrose, 1.0 mg/L 6-BA, and 0.2 mg/L 2,4-D at 25 °C. Under this system, ‘21-CJ46’ achieved a maximum embryo induction rate of 86.67%. Flow cytometry and chromosome counting indicated frequent spontaneous chromosome doubling, with regenerants mainly distributed as diploids and tetraploids. RNA-seq analysis comparing pre-induction (0 d) and 14 d ovaries showed extensive transcriptional reprogramming, including significant enrichment of phenylpropanoid biosynthesis, plant–pathogen interaction, and plant hormone signal transduction pathways. Differential expression analysis demonstrated that key embryogenesis regulators, such as BBM2, WUSCHEL9, LEC, PLT2, and ABI3, were regulated at 14 d. These results provide an induction protocol and molecular indications relevant to accelerating Chinese chive breeding. Full article

To identify adaptive cultivation strategies for strong-gluten winter wheat under conditions of increasing autumn temperatures and changing precipitation patterns in the Huang–Huai–Hai region, a field experiment was conducted with cultivars Jimai 44 and Zhongmai 578. Field experiments were conducted during the 2023–2024 and 2024–2025 growing seasons, using three sowing dates (T2–T4, 20 October to 3 November) in the first year and four sowing dates (T1–T4, 13 October to 3 November) in the second year, each combined with three seeding rates (M1–M3) that were increased by 52.5 kg ha⁻¹ for every 7-day delay in sowing. This design evaluated how sowing date and seeding rate regulate photosynthesis, dry matter dynamics, and yield. The results showed that post-anthesis dry-matter accumulation, harvest index, grain number per unit area, and grain yield responded quadratically to delayed sowing and increased seeding rate. Delayed sowing increased flag-leaf SPAD but reduced dry matter at anthesis and maturity, pre-anthesis translocation, spike number, and thousand-kernel weight. Higher seeding rate decreased SPAD, net photosynthetic rate, grains per spike, and kernel weight. The T2M2 treatment optimized canopy structure, enhanced photosynthesis, maintained efficient dry matter production and partitioning, and balanced yield components, achieving the highest grain yield. Although severe delays in sowing reduced yield, increasing the seeding rate under late sowing compensated for the reduced spike number and mitigated yield losses. The T2M2 combination and the late-sowing with the incremental-seeding technique offer practical strategies for climate-resilient, high-yield wheat production in the region. Full article

Aquilegia oxysepala is a characteristic wildflower of Northeast China, which has great application potential owing to its unique floral morphology and strong adaptability. The R2R3-MYB is one of the largest transcription factor families and has important roles in anthocyanin biosynthesis. A total of 90 AoMYBs were identified from A. oxysepala and divided into 29 subfamilies via phylogenetic analysis. Using bioinformatics methods, a systematic analysis was conducted on the physicochemical properties, gene structures, conserved motifs, and other characteristics of these genes. Based on the transcriptomic data of A. oxysepala and A. oxysepala f. pallidiflora across different floral developmental stages, 32 differentially expressed genes (DEGs) belonging to the R2R3-MYB family were screened, and their expression patterns were analyzed. The results indicated that AoMYB32 and AoMYB34 were significantly upregulated only at the pre-anthesis stage (PrA) in A. oxysepala, whereas their expression levels remained relatively low in A. oxysepala f. pallidiflora during the same stage. Correlation network analysis indicated that AoMYB34 was positively correlated with six functional genes associated with anthocyanin synthesis, namely PAL-2, C4H, 4CL, CHS, F3′5′H, and ANS. Reverse transcription quantitative PCR (RT-qPCR) validation revealed that AoMYB32 and AoMYB34 exhibited significant upregulation at the PrA stage in A. oxysepala, while their expression showed no obvious fluctuations across the entire flowering period in A. oxysepala f. pallidiflora. In summary, it is postulated that AoMYB32 and AoMYB34 are candidate genes associated with flower color variation formation of A. oxysepala. This study provides a theoretical basis and genetic resources for deciphering the mechanism of flower color formation and facilitating flower color improvement breeding in A. oxysepala. Full article

While persistent calyces exhibit considerable functional diversity, this has not been fully substantiated by experiments, especially concerning their thermoregulatory function. This study investigates the thermoregulatory function of persistent calyx in winter-flowering Brandisia hancei. Changes in calyx dimensions throughout the flowering-to-fruiting developmental stages were measured. Differences between floral and ambient temperatures were measured when only calyxes were retained. Additionally, differences in floral temperature between calyx-removed treatments and intact controls were also measured. All measurements were taken at three developmental stages: pre-anthesis, anthesis, and post-anthesis. Furthermore, seed production after calyx manipulation was examined at both anthesis and post-anthesis stages. The calyx exhibits continuous size enlargement from flowering to fruiting stages. After either artificial corolla removal or natural corolla abscission, the calyx independently maintains thermoregulatory capacity, sustaining floral temperatures significantly above ambient levels. Consequently, calyx removal resulted in markedly diminished floral temperature at both pre- and post-anthesis stages. In line with the thermoregulation results, progressive removal of the calyx showed a strong negative correlation with seed production. In contrast, removal of only the calyx edge generally maintained seed production at a level comparable to that of the intact control. Collectively, our findings demonstrate that the persistent calyx plays a critical role in elevating reproductive temperature under winter conditions, enhancing reproductive success in B. hancei through the maintenance of a favorable thermal conditions for reproduction. This study provides direct evidence that plant reproductive structures can markedly adapt to winter low-temperature stress through such a thermoregulatory mechanism. Full article

Lodging is a major constraint limiting wheat (Triticum aestivum L.) yield and quality globally. Despite dwarfing genes reducing plant height and mitigating lodging risk and losses, lodging still severely limits wheat yield. Few studies have examined how wheat breeding has altered the sensitivity of yield to lodging, especially its penalties in grain number and grain weight at specific spike positions. Two separate experiments were conducted in the Huang-Huai-Hai region of China: a lodging-period experiment (two genotypes, five periods) during the 2011–2013 growing seasons, and a lodging-angle experiment (three genotypes, five angles) during the 2019–2021 growing seasons. The results showed that grain number per m² (GNO), average grain weight (AGW), and grain yield (GY) all increased linearly with genotype release year. Lodging significantly reduced GNO and AGW, and consequently GY in all genotypes, but these losses declined linearly with the year of genotype release, indicating that modern genotypes suffer less yield penalty under lodging. Furthermore, lodging at any stage reduced the weight of both superior and inferior grains within the spike, whereas only pre-anthesis lodging decreased grain number per spike. Inferior grains, owing to their higher environmental sensitivity, showed larger reductions in both grain number and grain weight per spike than superior grains. Across all genotypes, lodging decreased grain number and grain weight per spike in the order apical > basal > central, and the relative losses declined linearly with year of genotype release. Moreover, lodging-induced losses in ¹³C assimilation followed the order old > intermediate > modern across genotype eras; the reduction in ¹³C assimilation within the spike ranked apical > basal > central, and that in superior grains exhibited the same pattern. Concurrently, the allocation of ¹³C assimilates to inferior grains was markedly inhibited across all spike positions, with the reduction magnitude significantly exceeding that in superior grains. Lodging-induced differential changes in ¹³C assimilation among grain positions within each spike layer are associated with the uneven reductions in grain number and average grain weight across the spike. These findings may provide a basis for lodging-resistant wheat production and cultivar breeding. Artificial lodging induction can serve as a reliable strategy to efficiently evaluate yield stability and lodging tolerance. However, its applicability to other wheat regions needs further verification via multi-location and multi-cultivar trials. Full article

Soil quality degradation and low nutrient use efficiency constrain sustainable maize–soybean rotation in the Albic soil region of Northeast China. A field experiment was conducted in 2023–2024 at Qixing Farm (Jiansanjiang, Heilongjiang, China) to evaluate chemical fertilizer combined with cattle manure or microbial inoculants. Five treatments were established: no fertilization (CK), chemical fertilizer alone (CF), chemical fertilizer combined with cattle manure (CF+CM), chemical fertilizer combined with a Bacillus subtilis inoculant (CF+CRA), and chemical fertilizer combined with a Bacillus megaterium inoculant (CF+CRB). Soil available nutrient dynamics, crop nutrient accumulation and translocation, fertilizer use efficiency, and yield were assessed. In maize, CF+CRB significantly enhanced pre-anthesis N translocation and post-anthesis P accumulation, increasing grain yield to 14,533 kg ha⁻¹ (+28.6% vs. CF). In soybean, CF+CRB produced 3328.15 kg ha⁻¹, 15.8% higher than CF. CF+CRA significantly increased soil available P during the soybean flowering-pod stage and improved K allocation at later stages. Overall, integrating chemical fertilizer with CRB improved yield and nutrient use efficiency. Based on crop-specific nutrient requirements, CRB is recommended for the maize season to strengthen nutrient translocation, whereas cattle manure or CRA can be applied in the soybean season to sustain K supply. Full article

Hollowness of the cucumber fruit, caused by carpel separation during growth, severely impacts fruit quality. Several Sikkim cucumber accessions originating from the India–Pakistan region exhibit pronounced internal cavities. We previously identified the QTL mfh2.1 as a key contributor to this phenotype. In this study, we investigated the genetic and physiological basis of fruit hollowness in the Sikkim cucumber line WI7120 through an integrative analysis combining histological staining, HPLC for hormonal profiling, and fine mapping using a large F2 segregation population. Comparative analysis between the hollow-fruited WI7120 and the non-hollow line 9930 revealed distinct growth dynamics: WI7120 displayed accelerated radial expansion and aberrant cell patterning at carpel junctions. Histological examination using paraffin sectioning uncovered disorganized endocarp cell arrangements in WI7120 occurring as early as pre-anthesis (0 days post-pollination), with enlarged suture cells that likely facilitate tissue separation during fruit enlargement. Hormonal assays indicated elevated levels of gibberellin (GA) and zeatin (ZT), along with reduced indole-butyric acid (IBA) in WI7120, suggesting that a hormonal imbalance and mechanical stress contribute to compromised cell adhesion. By screening ~2000 F₂ individuals with SSR and InDel markers, we refined the mfh2.1 locus to a 50.92 kb interval on chromosome 2, pinpointing CsRPT4Bb—encoding a 26S proteasome subunit—as the candidate gene. A non-synonymous SNP (I135V) in CsRPT4Bb was associated with tissue-specific expression patterns during cavity formation, implicating proteasome-mediated cellular remodeling in carpel cohesion. Spatial-temporal expression analysis further revealed upregulation of CsRPT4Bb in the WI7120 exocarp during fruit expansion, potentially influencing cell wall dynamics. This study demonstrates a coordinated interplay among genetic, hormonal, and mechanical factors underlying cucumber fruit hollowness, offering new avenues for breeding cultivars with improved fruit integrity and postharvest quality. Full article

Climate change has intensified drought events, compromising popcorn production, particularly in tropical regions. This study aimed to identify popcorn inbred lines with superior water-use efficiency and responsiveness, and to examine the relationships among morpho-agronomic traits associated with expanded popcorn volume per hectare (VP). Fifty inbred lines were evaluated under well-watered (WW) and water-stressed (WS) conditions across two cropping seasons (2020 and 2021). Water deficit was imposed at pre-anthesis, with the permanent wilting point occurring during early reproductive stages in 2020 and during grain filling in 2021. Principal component analysis and efficiency/responsiveness classification were used to characterize line performance. Significant genotype × water condition × season interactions affected all traits. Water stress reduced VP by 75% in 2020 and 46% in 2021, reflecting the differing timing of stress. Line L477 showed high efficiency and responsiveness, while genotypes such as L213, L221, and L222 were inefficient and non-responsive in both years. Under WW, VP was mainly associated with hundred-grain weight, ear length, and grain number per row, whereas under WS, ear diameter and number of rows per ear were the strongest contributors, indicating that the available genetic variability is more effectively exploited through selective morpho-agronomic criteria tailored to each water scenario. Contrasting crosses between efficient and non-responsive lines (L325 and L481) and inefficient but responsive lines (L513, L625, and L689) are recommended to support the development of hybrids that combine high yield under irrigation with resilience under water-stress conditions. Full article

Irrigation practices and nitrogen (N) addition play pivotal roles in wheat production, and their rational coordination can significantly enhance N, phosphorus (P), and potassium (K) use efficiency and yield of wheat. However, the comprehensive effects of irrigation practices and N addition rates on N, P, and K accumulation and utilization and yield of wheat in dryland remain unclear. A field experiment with two irrigation practices (W0, zero-irrigation and W1, one-off irrigation), and four N addition rates (0, 120, 180, and 240 kg N ha⁻¹, represented by N0, N120, N180, and N240, respectively) was conducted in 2021–2022 and 2023–2024. Compared to W0N0, W1N180 significantly increased wheat grain yield, spike number, and grains per spike by 46.4%, 35.9%, and 18.9%, respectively. Wheat yield and N, P, and K accumulation reached the maximum value at N180 or N240. One-off irrigation significantly improved the uptake efficiency and fertilizer partial factor productivity for N, P, and K, whereas increased N addition enhanced these parameters specifically for P and K. However, N180 treatment increased N uptake efficiency, N fertilizer partial factor productivity, P internal efficiency, and K internal efficiency by 22.2%, 31.1%, 9.4%, and 5.9%, respectively, compared to N240 under one-off irrigation. In addition, W1N180 significantly increased above-ground N, P, and K accumulation by 45.8%, 52.8%, and 51.8%, as well as pre-anthesis N and P translocation by 48.5% and 47.0%, respectively, compared to W0N120. Consequently, the W1N180 strategy not only improved wheat yield but also optimized N, P, and K accumulation, pre-anthesis N and P translocation, and nutrient use efficiency. Therefore, one-off irrigation combined with N180 can be recommended for enhancing wheat yield and nutrient use efficiency in dryland. Full article

While pursuing high yields, China’s maize industry is facing a series of complex challenges that not only affect production efficiency but also relate to the sustainable development of the industry. Maize varieties with different nitrogen use efficiencies (NUEs) significantly influence yield. Therefore, investigating the response mechanisms of maize varieties with varying NUEs to nitrogen fertilization can provide theoretical foundations and technical support for achieving high and stable yields, as well as for the breeding of new varieties. Based on previous research findings, this experiment selected three maize varieties with different NUE levels. A field trial was conducted with eight nitrogen fertilization gradient levels to analyze their responses to varying nitrogen inputs, thereby further evaluating the performance of maize varieties with different nitrogen use efficiencies. The results indicated that increasing nitrogen application significantly enhanced maize yield; however, with continued nitrogen application, the yield exhibited a trend of initial increase followed by a decrease or stabilization. The highest yields for Jingpin 450 (JP450), Xianyu 335 (XY335), and Qiule 368 (QL368) were achieved under the N250, N300, and N250 treatments, respectively, reaching 8.9 t·ha⁻¹, 9.2 t·ha⁻¹, and 10.1 t·ha⁻¹. Across all nitrogen treatments, QL368 > XY335 > JP450. Maize varieties with high nitrogen efficiency maintained higher post-anthesis nitrogen accumulation throughout the growth period, thereby promoting the translocation of post-anthesis nitrogen to the grains, increasing grain nitrogen content at maturity, and ultimately improving yield. The dual-high-efficiency maize variety QL 368 (QiuLe 368) achieved high yields under both low- and high-nitrogen conditions, primarily due to its high pre-anthesis nitrogen translocation rate and substantial post-anthesis nitrogen accumulation. This enhanced nitrogen translocation to the grains, improved nitrogen use efficiency, further strengthened the plant’s dry matter production capacity, and ultimately led to high yield and efficiency in maize production. Full article

One of the main factors influencing wheat productivity is nitrogen (N) management. This study examined the impact of varying N-fertilizer rates on spring wheat yield and N use efficiency by adjusting the “source-sink” relationship between assimilates and N accumulation and transport. The objective was to identify the optimal N rate for the region. The field experiment included five N-fertilizer rates: 0 kg ha⁻¹ (N1), 52.5 kg ha⁻¹ (N2), 105.0 kg ha⁻¹ (N3), 157.5 kg ha⁻¹ (N4), and 210.0 kg ha⁻¹ (N5). Results indicated that the yield response was not proportional to N-fertilizer rates, with maximum biomass (6029 kg ha⁻¹) and grain yield (2625 kg ha⁻¹) achieved under N3. N fertilization primarily increased yield by regulating pre-anthesis translocation of assimilate and N. Assimilate translocation peaked at 105 kg N ha⁻¹, increasing by 8.5–133.7% compared to other treatments. With increasing N input, N absorption efficiency and N partial factor productivity declined. The highest N agronomic use efficiency was observed under N3, which was 19.5–176.34% higher than other treatments. Overall, moderate N input (≈105 kg ha⁻¹) optimizes yield and N-use efficiency, offering guidance for sustainable N management in dryland spring wheat production. Full article

Megalurothrips usitatus (Bagrall 1913) (MTU) is a major pest of cowpea (Vigna unguiculata (L.) Walp.) and shows a strong preference for floral tissues. To clarify the spatiotemporal distribution of thrips, we conducted a detailed survey of their abundance in flowers of different developmental stages—sampled in the morning (preanthesis flowers, PAF; open flowers, OPF; postanthesis flowers, PoAF) and at dusk (preanthesis flowers scheduled to open the next morning, PAF-D; closed flowers, CF). Behavioral responses of MTU to floral volatiles from these stages were evaluated using a Y-tube olfactometer, followed by chemical analysis via gas chromatography–mass spectrometry (GC-MS). The results indicate that 58.3% of adults sheltered in keel petals, while 76.7% of nymphs aggregated inside the diadelphous stamens. Thrips abundance on OPF in the morning was significantly higher than on PAF or PoAF, but did not differ significantly from that on CF. Olfactometric assays demonstrated a clear preference of MTU for OPF, which emitted a greater number and higher concentrations of volatile compounds compared to PAF, PAF-D, CF, and PoAF. Together, these findings reveal distinct spatiotemporal dynamics of thrips in relation to cowpea flower development, underscoring the role of floral age in driving host-switching behavior. Full article

Gynogenesis offers a promising route for doubled haploid (DH) production in Cucurbita, yet efficient protocols remain scarce. This study established a reproducible ovary culture system for Cucurbita pepo and evaluated zeatin riboside (ZR) as an alternative cytokinin. Ovaries collected at anthesis and one day before were cultured to screen nine media with different cytokinin–auxin combinations. Subsequently, four optimized ZR-based formulations were evaluated. Both floral stages showed morphogenic activity, but embryo formation occurred almost exclusively in pre-anthesis ovaries. Among ZR treatments, E6.1 (1 mg·L⁻¹ ZR + 3 mg·L⁻¹ NAA, 30 g·L⁻¹ sucrose) achieved the highest embryogenic output (approximately 97 embryos per 100 explants), while high-sucrose media (120 g·L⁻¹) induced abundant swollen ovules but poor conversion, suggesting that excessive osmotic pressure promotes morphogenesis but hampers embryogenic transition. In total, 415 embryos were obtained, and 52 regenerants were analyzed by flow cytometry, confirming haploid, diploid, and mixoploid plants and evidencing spontaneous chromosome doubling during in vitro development. A categorical A–D scoring system enabled early prediction of embryogenic potential. This represents the first successful application of ZR in cucurbit gynogenesis and highlights its value as a biologically compatible cytokinin for DH production. The findings open new avenues for testing ZR-based formulations in other Cucurbita species under different auxin and sucrose regimes. Full article

Boron exerts regulatory control over various aspects of plant growth and morphogenesis, and the application of boron prior to anthesis has been recognized as a critical agronomic practice. However, the regulatory mechanisms by which boron influences fruit set and early ovary development in pear remain to be elucidated. In this study, boron application was used at three stages, including pre-flowering, full-flowering, and early fruiting in the ‘Kuerle Xiangli’ (Pyrus sinkiangensis Yu), with a focus on cell expansion and endogenous phytohormone. As a result, treatment with 0.3% boric acid significantly increased endogenous boron concentrations in both leaves and ovaries and enhanced ovary fresh weight as well as both longitudinal and transverse diameters. Histological analysis revealed pronounced cell expansion at 5, 10, and 15 days after pollination (DAP) following boron treatment. Furthermore, gibberellin and trans-zeatin concentrations at 5 and 10 DAP were significantly elevated, while the concentrations of abscisic acid and auxin were markedly reduced. Quantitative real-time PCR (qRT-PCR) analysis demonstrated that boron positively regulates the expression of auxin-related genes, like PbARFH, PbARFD and PbSAUR76-like. In the gibberellin signaling pathway, the expression PbGID1, PbGID1C-like and PbGID2 was activated to drive cell expansion with the boron application. In the abscisic acid signaling pathway, boron treatment induced downregulation of PbSRK2.4, PbABF2, and PbABF2-like in the ovary. Furthermore, boron treatment induced high expression of hormone signaling genes in cytokinin, brassinolide, jasmonic acid and salicylic acid signaling pathways. These findings provide insights into the mechanisms of cell expansion and hormonal changes by which boron modulates early ovary development, offering a basis for improving fruit quality through optimized boron application. Full article

In the Mediterranean region, the persimmon cultivar ‘Rojo Brillante’ may experience up to four waves of fruit drop. The first is a physiological event during fruit set that is common in woody species, while the subsequent waves are induced by rising temperatures and prolonged summer water stress. These summer drops represent the main limiting factor, leading to yield losses of up to 90%. Organ abscission is a complex process regulated by genetic, hormonal, nutritional, and environmental factors. We hypothesise that calcium (Ca) plays a protective role in the abscission zone (AZ) by inhibiting cell wall-degrading enzymes such as polygalacturonase (PG) and pectin methylesterases (PMEs). Calcium applications every 15 days from anthesis onwards significantly reduced fruit drop. Treatments preserved polar auxin transport—through DkPIN1 expression—and inhibited stage C of the abscission process, decreasing the relative expression of the DkIDL6 gene in the AZ. Moreover, PME and PG activities were significantly lower in Ca-treated fruits, confirming the stabilising effect of calcium on AZ integrity. In summary, pre-anthesis calcium sprays reduced premature fruit drop by about 30% under heat–drought stress by down-regulating key abscission genes (DkIDL6, DkPG20, DkPME41) and preserving cell wall integrity and fruit firmness, supporting the use of Ca treatments as a climate-smart approach to stabilise persimmon yield. Full article