Sugarcane family evaluation is a key technical method for screening excellent sugarcane hybrid combinations and assessing the breeding value of parents. In this study, 86 sugarcane hybrid combinations were used as the materials for family evaluation. Over consecutive years, investigations were carried out on yield-related traits (plant height, tillering and clump mass), sugar-content traits (brix), and disease/pest resistance traits (smut, top rot, and dead heart seedlings). Subsequently, key evaluation indicators for each trait, including heritability, combining ability, breeding value, and coefficient of variation, were calculated. By employing correlation analysis, principal component analysis, cluster analysis, and economic breeding value estimation, the field performance of each hybrid combination and the genetic contributions of the parents were comprehensively evaluated from multiple dimensions. For yield-related traits, cluster weight had an extremely significant positive correlation with both plant height and tiller number (P<0.01). Through principal component analysis, 5 high-yield hybrid combinations (Guitang 04-1545×Zhongtang 12-02) were screened out. Meanwhile, parents including female parent Q208 and male parent XTT22 exhibited outstanding GCA and possessed excellent genetic transmission capacity for yield. For disease and pest resistance traits, the incidence rates of smut and pokkah boeng disease showed an increasing trend year by year with the observation period, while the incidence rate of dead heart seedlings decreased annually. Among them, 5 hybrid combinations (Yuetang 03-373× CP84-1198) exhibited strong comprehensive disease resistance. For sugar-related traits, 5 hybrid combinations (Yunzhe 05-51×Guitang 00-122) performed excellently in brix value and specific combining ability (SCA). Additionally, parents including female parent Yunrui 15-90 and male parent Guitang 04-1001 showed significant high-sugar genetic characteristics, making them excellent parent materials for breeding high-sugar varieties. In the comprehensive trait evaluation, the results of principal component analysis and cluster analysis mutually verified each other. Finally, hybrid combinations with excellent comprehensive performance (LCP85-384×Yuetang 94-128) and core parents with outstanding comprehensive traits (including female parent Guitang 04-1545 and male parent XTT22) were screened out. The results of the study could provide important references for the directional breeding of specialized sugarcane varieties with high yield, high sugar content and disease resistance, as well as the scientific selection and matching of parents in hybrid breeding.

A systematic multi-trait assessment was conducted using principal component analysis, membership function method, and cluster analysis to comprehensively evaluate the agronomic performances of 15 Yunzhe-type innovative sugarcane germplasm lines in Kaiyuan, Yunnan and identify superior parents for high-yield and high-sugar breeding. The main cultivated variety Yunzhe 05-51 was used as the control. Nine key agronomic traits, plant height (PH), stalk diameter (SD), single stalk weight (SSW), millable stalk number per hectare (MSPH), cane yield (CY), fiber content (FC), juice extraction rate (JE), apparent purity (AP), and sucrose content in cane (SC) were measured under both plant cane and first ratoon conditions. The results showed that the coefficients of variation for the traits ranged from 4.81% to 21.02%, with single stalk weight and cane yield exhibiting the greatest variation. Correlation analysis indicated that plant height, stalk diameter, and single stalk weight were significantly positively correlated with cane yield. Principal component analysis extracted three principal components, which together accounted for 82.436% of the total variance, representing yield structure, sugar quality, and stalk population characteristics, respectively. Based on the comprehensive evaluation D-values derived from the membership function method, there were 11 materials higher than the control. They were ranked as follows from high to low, Yunzhe 2018-124>Yunzhe 2018-95>Yunzhe 2018-120>Yunzhe 2017-121>Yunzhe 2018-92>Yunzhe 2016-166>Yunzhe 2017-131>Yunzhe 2016-145>Yunzhe 2014-170>Yunzhe 2014- 224>Yunzhe 2014-222>Yunzhe 05-51. Cluster analysis classified the germplasm into three groups. Group Ⅰ was identified as the high-yield type, and Group Ⅲ as the high-sugar type. Further screening identified the germplasm with outstanding single traits. High-yield types included Yunzhe 2017-121, Yunzhe 2018-124, and Yunzhe 2018-95. High-sugar types included Yunzhe 2014-222, Yunzhe 2016-145, and Yunzhe 2017-152. High-fiber types included Yunzhe 2017-152 and Yunzhe 2018-120, which are suitable as the parents for breeding mechanization-adapted varieties. Both Yunzhe 2018-124 and Yunzhe 2018-95 demonstrated excellent performances in yield and quality related traits, indicating a high potential as core parents for high-yield and high-sugar sugarcane breeding. The materials could provide valuable germplasm support for sugarcane variety selection in Yunnan and other ecologically similar regions.

Phytochrome-interacting factors (PIFs) are key transcription factors that regulate plant photomorphogenesis and play important roles in plant growth, development, and responses to environmental stresses. To date, PIF gene family have been identified in many plant species; however, systematic identification and analysis of the PIF gene family in Saccharum spontaneum L., a wild relative of sugarcane, have not yet been reported. In this study, the PIF gene family in S. spontaneum (SsPIF) was identified, and comprehensive analyses were conducted on the physicochemical properties of the encoded proteins,chromosomal localization, intra- and interspecific synteny relationships, and cis-acting elements in promoter regions. In addition, quantitative real-time PCR (qRT-PCR) was used to analyze the expression patterns of SsPIF genes in different tissues of sugarcane and under three plant hormone treatments. The results showed that 12 SsPIF gene were identified from the S. spontaneum genome. These genes encode proteins ranging from 435 to 765 amino acids in length, with molecular weights between 48.14‒83.91 kDa. The predicted isoelectric points (pI) ranged from 5.59 to 6.97; most SsPIF proteins had pI values close to neutral, while a few tended to be acidic or basic. Subcellular localization analysis indicated that all SsPIF proteins are localized in the nucleus. Chromosomal mapping revealed that the SsPIF genes are unevenly distributed across 10 chromosomes. Multiple sequence alignment demonstrated that all SsPIF family members contain conserved basic helix–loop–helix (bHLH) and APB domains, while members of the SsPIF3 subgroup possess a unique APA domain. Comparative synteny analysis showed that fourteen orthologous gene pairs exist between S. spontaneum and rice. Promoter analysis revealed that SsPIF genes are enriched in cis-acting elements related to light responsiveness, hormone signaling, and stress responses. The expression profiles of SsPIF genes exhibited clear tissue specificity, indicating their involvement in the growth and development of S. spontaneum. Furthermore, qRT-PCR analysis revealed distinct expression patterns of the twelve SsPIF genes in response to methyl jasmonate, gibberellin, and auxin treatments. Overall, these findings provide a solid foundation for further functional characterization of the SsPIF gene family and for elucidating their roles in regulating growth, development, and signal transduction pathways in S. spontaneum.

The study was aimed to explore the effects of reducing chemical fertilizer application combined with microbial fertilizer on the quality of cempedak [Artocarpus champeden (Lour.) Spreng.] and soil nutrients. 7-year-old Duoyi No.1 cempedak was used as the material and 6 treatments, 100% compound fertilizer treatment (CK, 2 kg), 20% reduction in compound fertilizer + 20% microbial fertilizer (T₁), 40% reduction in compound fertilizer + 40% microbial fertilizer (T₂), 60% reduction in compound fertilizer + 60% microbial fertilizer (T₃), 80% reduction in compound fertilizer + 80% microbial fertilizer (T₄), and 100% microbial fertilizer treatment (T₅, 5 kg) were set up. The effects of different fertilization treatments on cempedak quality, the effects of soil nutrients, and the correlation between cempedak quality index and soil nutrient index were analyzed. Compared with CK and T₅ treatments, other treatments increased the fruit weight, edible rate, single aril pit weight, single aril weight, and soluble solids content of cempedak, reduced the fruit wall thickness. The T₃ and T₄ treatments significantly increased the single fruit weight and single aril weight of cempedak. The combined application of microbial fertilizer had a certain promoting effect on soil nutrients. The T₄ treatment significantly enhanced soil total nitrogen, available phosphorus, available potassium, organic matter, and pH, while also increasing the levels of six metal elements in the soil: Ca, Mg, Fe, Mn, Cu, and Zn. The T₃ treatment was second only to T₄ treatment. Correlation analysis showed that the combined application of microbial fertilizer improved the single fruit weight and single aril weight of cempedak mainly by increasing available phosphorus, available potassium, Fe and Mn in the soil. In conclusion, the treatments of T₃ and T₄ not only improved the yield and quality of cempedak, but also improved the soil environment and ecological benefits, which are the optimal combined application modes for green and efficient cultivation of cempedak.

Sugarcane (Saccharum spp.) is the most significant global sugar crop, contributing approximately 80% of total sugar production worldwide. Developing high-yielding and high-sugar-content varieties is critical for enhancing sugar industry sustainability. To support this goal and optimize hybrid breeding strategies, this study evaluated 71 sugarcane hybrid combinations derived from 75 parental lines, using six key agronomic traits: plant height, stalk diameter, brix (juice sugar content), number of effective stalks, cane yield and sugar yield. The main objective was to assess general combining ability (GCA) and specific combining ability (SCA), to identify superior parental lines and hybrid combinations for sugarcane breeding programs. The GCA/SCA analyses were performed using the R software. Clustering analyses were conducted based on combining ability values to classify parental materials and hybrid combinations into distinct genetic performance groups. Results showed substantial genetic variation across hybrids, particularly in yield-related traits, with coefficients of variation exceeding 39.00% for effective stalks, cane yield and sugar yield, highlighting significant breeding potential. Conversely, brix exhibited the lowest variation (8.05%), indicating high genetic stability for sugar content traits. Notably, HoCP05-902, GT96-211, YT93-124, YT93-159, GT00-122 and YR05-704 were identified as elite male parents, while GT94-119, CP72-1210 and Eros were outstanding female lines. Two combinations, CP72-1210×GT96-211 and GT94-119×YT93-159, exhibited superior GCA and SCA values, achieving excellent performance in both yield and sugar content. Additionally, GCA/SCA ratio analysis revealed that cane yield exhibited significant additive effects primarily inherited from the male parent. In conclusion, this research provides valuable theoretical guidance and genetic resources for sugarcane breeding, highlighting key parental lines and hybrid combinations that can serve as core materials in developing next-generation high-yield, high-sugar sugarcane cultivars.

The study aimed to investigate the physiological responses of intergeneric hybrid Erianthus arundinaceus× Saccharum spontaneum L offspring at the seedling stage under drought stress, to identify novel sugarcane germplasm resources with better drought stress tolerance. The results would provide a theoretical basis for breeding and utilizing drought-tolerant new sugarcane varieties. Thirteen hybrid progenies and the sugarcane variety ROC22 were used as the experimental materials in a barrel experiment. The contents of malondialdehyde (MDA), soluble sugars (SS), soluble protein (SP), proline (PRO), and the activities of peroxidase (POD) and superoxide dismutase (SOD), were measured in sugarcane seedling leaves under mild and severe drought stress, and control (normal watering). A comprehensive evaluation of drought tolerance in thirteen progenies and ROC22 was conducted based on drought resistance coefficients, membership function values, and the comprehensive drought tolerance evaluation index (D value), to screen and identify drought-tolerant sugarcane germplasm resources. Under different drought treatments, the content of SS, SP, PRO, MDA, and the activities of SOD and POD were elevated in the seedling leaves of hybrid progenies. Notably, under severe drought stress, the physiological indicators of AS08-2-28 were significantly higher than those of ROC22. Based on the D value, seven progenies exhibiting greater drought tolerance than ROC22 at the seedling stage were identified, ranked as follows: AS08-2-28>AS11-1-101>AS11-4-44>AS11-75-1>AS12-A6-21>AS12-A6-5>AS12-176-5. This study evaluated the drought tolerance of the hybrid progenies at the seedling stage and successfully screened seven sugarcane germplasm resources with strong drought resistance. The findings would provide a foundational basis for the future mining of drought-related genes and offer scientific guidance and experimental support for the effective utilization of intergeneric hybrid complex offspring in breeding new sugarcane varieties with enhanced drought tolerance.

Long-term subculture preservation significantly impacts somatic embryogenesis (SE) in various plant species. Studies on its effects in litchi (Litchi chinensis Sonn.) remain scarce. This study aimed to investigate the effects of subculture times on SE in litchi embryogenic callus (EC) and to uncover the metabolic basis for its decline, thereby providing a theoretical foundation for improving SE efficiency. Using 'Feizixiao' litchi EC materials from different subculture times (denoted as J11, J22, J48, J65 and J86). Somatic embryo induction rate, phenotypic characteristics, and dynamic changes in soluble sugars, organic acids, free amino acids, and energy-related substances were measured. The results showed that subcultures times significantly influenced SE in litchi EC. The embryo induction rate initially increased and then decreased with increasing subculture times, while the yield of normal somatic embryos (monocotyledonous, dicotyledonous, and polycotyledonous embryos) was also significantly affected. Among the five groups, J22 exhibited the highest induction rate (257.33%) and the greatest number of milky-white embryos. Sucrose content showed a significant positive correlation with SE, highlighting its role as the key carbon source for litchi SE. Fluctuations in soluble sugar content were primarily attributed to variations in sucrose. Low-subculture materials (J11 and J22) showed significant decreases in citric acid, succinic acid, and malic acid during the middle-late SE induction stages, indicating a stronger tricarboxylic acid (TCA) cycle flux compared to high-subculture materials (J48, J65, J86). The total amino acid content in EC initially increased and then stabilized during SE induction, with low-subculture materials maintaining higher overall amino acid levels. The contents of two major amino acids (glutamine and alanine) were significantly more abundant in low-subculture materials. Furthermore, the contents of adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) initially increased and then decreased, with AMP being the most abundant. Low-subculture materials maintained significantly higher AMP levels during the first 49 days of SE induction, particularly in J22. The results demonstrate that subculture times is a critical factor influencing SE in litchi EC. Long-term subculture induces embryogenic decline by impacting energy supply and amino acid metabolism.

Plants are prone to low inorganic phosphorus (Pi) abiotic stress, which has adverse effects on the growth, development and physiological metabolic processes. Camellia hainanica, a local variety in Hainan, mostly grows in low-phosphorus environments. C. hainanica has unique genetic characteristics that distinguish it from C. oleifera. In this study, a tropical cultivar Haida Oil-tea 4 (H4) was used as the research object to screen reference genes suitable for quantitative real-time polymerase chain reaction (qRT-PCR) analysis of C. hainanica under low Pi stress. The expression levels of six candidate reference genes, EF1α1, GAPDH, Actin, UBQ, ETIF3H and TUB2, were detected by qRT-PCR. The stability of each reference gene was comprehensively evaluated using ΔCt, geNorm, NormFinder, BestKeeper software and RefFinder online analysis tools, and ETIF3H was identified as the optimal reference gene. Using ETIF3H as the reference gene, we validated the expression levels of three low Pi responsive genes. The results showed that the target genes were differentially expressed in response to low Pi, indicating that ETIF3H is suitable as a reference gene for detecting gene differential expression under low Pi stress conditions. This work would provide appropriate reference genes for transcript normalization in H4 under low Pi stress, which will facilitate subsequent study of phosphorus signal-response gene expression in C. hainanica.

The glyoxalase system, comprising glyoxalase I (GLYI) and glyoxalase II (GLYⅡ), serves as a key mechanism for detoxifying excess methylglyoxal (MG) in plants and plays an important role in responses to abiotic stress and pathogen infection. To date, genome-wide identification and expression analysis of GLY gene family have not been reported in sugarcane. In this study, we identified 50 SsGLYI genes and 52 SsGLYⅡ genes from the wild sugarcane Saccharum spontaneum, and systematically analyzed the physicochemical properties, gene structures, promoter cis-acting elements, and expression patterns. SsGLY genes were randomly distributed across 30 chromosomes. All 43 SsGLYI members contained a conserved Motif1 (PF00903), while all SsGLYII proteins possessed a conserved Motif1 (PF00753). A total of 39 SsGLYI proteins contained four metal-binding sites (H/Q, L, H, E), except SsGLYII8.1-8.4 from subfamily IV, which were Zn²⁺-dependent, the remaining SsGLYI proteins were Ni²⁺-dependent. Only 26 SsGLYI proteins contained both the THxHxDH metal-binding domain and the C/GHT active site. Collinearity analysis identified 41 pairs of collinear genes, among which 39 pairs had Ka/Ks values less than 1, indicating that the SsGLY gene family has undergone predominant purifying selection during evolution. The expression levels of SsGLYI subfamily V and SsGLYⅡ subfamily Ⅲ were higher than those of the other four subfamilies under infection by Sporisorium scitamineum. Notably, the expression of SsGLYI3.4 showed differences in its expression patterns between the resistant genotype YT93-159 and the susceptible genotype ROC22. Furthermore, we cloned the homologous gene ScGLYI-1 of SsGLYI3.4 from YT93-159, which was constitutively expressed and primarily localized to the chloroplast. Meanwhile, the expression of ScGLYI-1 could be up-regulated by exogenous salicylic acid (SA) and smut pathogen stress, indicating that this gene may play a crucial role in response to pathogen stress in sugarcane. This study would provide a theoretical foundation for further elucidating the function of glyoxalase genes in sugarcane.

Sugarcane is a globally important cash crop and bioenergy crop, playing a critical role in promoting economic development in sugarcane-producing countries. Phosphorus is an essential nutrient for plants, and low phosphorus availability in soil often constrains the quality and yield of sugarcane in China. S. officinarum serves as an important genetic foundation for modern sugarcane varieties. Elucidating the low-phosphorus tolerance mechanisms in phosphorus-efficient genotypes of S. officinarum is of significant theoretical and practical importance for screening and breeding phosphorus-efficient sugarcane varieties, improving phosphorus fertilizer utilization efficiency, and promoting the development of the sugarcane industry. The study was aimed to explore the response characteristics of different S. officinarum genotypes under low-phosphorus stress from the perspectives of root morphology and physiological adaptations, identify key factors affecting phosphorus absorption, and provide a theoretical basis for improving nutrient utilization efficiency in sugarcane through root plasticity modification. Phosphorus-efficient S. officinarum genotypes (48 Mouna and Loether) and phosphorus-inefficient genotypes (NC20 and Badila) were used in the study. Under two phosphorus supply conditions, low phosphorus (0.2 μmol/L KH₂PO₄) and normal phosphorus (1000 μmol/L KH₂PO₄), comparative analyses were conducted on root morphological indices, low-phosphorus tolerance indices, root activity, acid phosphatase activity, and other physiological characteristics of each variety. The results indicated that low-phosphorus stress could inhibit the growth and development of various sugarcane tropical varieties to different degrees. Among them, the phosphorus-efficient variety Loether was the least affected by low-phosphorus stress in terms of plant height, stem dry weight, and whole-plant biomass, while its root dry weight and root-to-shoot ratio significantly increased. Low-phosphorus stress promoted increases in total root length, total root surface area, and total root volume in both Loether and 48 Mouna, with Loether exhibiting the most pronounced increase. The specific root length, specific root surface area, and specific root volume of most varieties decreased, with NC20 showing the greatest reduction. Additionally, all varieties exhibited root thinning. Furthermore, under low-phosphorus stress, 48 Mouna and Loether demonstrated higher root low-phosphorus tolerance indices, root activity, and phosphorus acquisition capacity. In conclusion, this study reveals that the phosphorus-efficient tropical varieties 48 Mouna and Loether can better optimize root architecture, enhance phosphorus absorption interfaces, maintain strong root activity and enzymatic adaptability, effectively improve phosphorus absorption and utilization efficiency, and exhibit strong adaptability to low-phosphorus stress.