To reveal the genetic basis of important economic traits in Dendrocalamus latiflorus, elucidate the patterns of genetic variation, and to accelerate the process of genetic improvement and precision breeding.

Eight geographically diverse D. latiflorus provenances were evaluated, with provenance codes LZ-1, LZ-2, LZ-3, LZ-4, BS, YD, JY, and FJ. Seedling stage phenotypic variation was analyzed by assessing above- and below-ground morphological traits and biomass. Genetic parameters were estimated. Superior provenances were identified using membership function for comprehensive evaluation.

11 phenotypic traits showed significant (P<0.05) or extremely significant (P<0.01) differences among different provenances of Ma bamboo (Dendrocalamus latiflorus). Among them, provenance YD had the highest number of shoots (8.83); provenance LZ-4 had the highest values for leaf expansion number, average root length, leaf area, ground diameter, and plant height (25.63, 9.76 cm, 9 566.77 mm², 19.70 mm, 2.96 cm, respectively); provenance LZ-3 had the highest number of roots, average root diameter, root biomass, and culm number (23.19, 1.22 mm, 1.20 g, 1.64, respectively); provenance FJ had the largest culm biomass (82.93±24.46 g). The genetic coefficient of variation for each trait ranged from 0.34% to 36.92%, and heritability (H²) exceeded 0.50 for all traits; heritability was extremely high for plant height (0.96), culm number (0.95), leaf area (0.94), ground diameter (0.92), and number of shoots (0.89). Correlation analysis showed that the number of bud emergence was significantly (P<0.05) or extremely significantly (P<0.01) positively correlated with leaf expansion number, mean root length, mean root diameter, bud biomass, and leaf biomass. Leaf area was extremely significantly (P<0.01) positively correlated with bud biomass, leaf biomass, root biomass, total biomass, and culm number. Regarding phenotypic genetic gain for each trait, provenance LZ-4 was the most prominent, with positive genetic gains for multiple traits, including number of shoots (2.53%), leaf expansion number (7.03%), average root length (1.84%), bud biomass (2.56%), leaf biomass (1.24%), and ground diameter (2.23%). Based on principal component analysis, four principal components were extracted, with a cumulative contribution rate of 79.034%, covering key phenotypic characteristics such as growth activity, root development, and biomass accumulation of Ma bamboo. The comprehensive evaluation results showed that provenance LZ-4 had the highest comprehensive score (1.179).

The eight provenances of Ma bamboo showed differences in seedling traits, among which provenance LZ-4 performed best, followed by JY, BS and LZ-2.

The dynamic changes of morphological and physiological characteristics of Phyllostachys edulis seeds during their development were revealed, which provided reference for macro-control and obtaining high-quality seeds.

The seeds of P. edulis were collected from Yangshan area of Guilin. The morphological and physiological indexes of P. edulis were observed and measured in different periods after flowering.

(1) From 10 to 30 days after flowering, the embryo and endosperm cells of P. edulis seeds had vigorous activity of division and differentiation, and the length, width and thickness of seeds increased rapidly. The seed embryo and endosperm cells entered the mature stage in 40 to 60 days after flowering, and the growth rate of seed length, width and thickness slowed down. (2) There were significant differences in the contents of soluble sugar, crude starch and soluble protein in the seeds at different development stages (P < 0.05). The contents of soluble sugar and crude starch showed unimodal curve changes, and the contents of soluble protein fluctuated in the range of 4.89%-5.82%. (3) There were significant differences in the content of reactive oxygen species and the activity of antioxidant enzymes (P < 0.05). The H₂O₂ content showed a unimodal curve with the activities of POD and CAT, while the O₂^- content showed a similar trend with the activity of SOD. (4) There were significant differences in the contents of endogenous hormones in the seeds at different developmental stages (P < 0.05). The contents of IAA, GA₃ and ZR showed a trend of “first increase, then decrease and then increase”, while the ABA content showed a single-peak curve, and the ratio of (IAA+GA₃+ZR)/ABA showed a trend of “first decrease and then increase”. The minimum value was 1.001 at the 40th day after anthesis.

The activity of antioxidant enzymes and the content of endogenous hormones increased gradually from 10 to 30 days after anthesis, which effectively promoted the metabolism, division and differentiation of seed cells of bamboo. From 30 to 60 days after anthesis, the differentiation of bamboo seeds basically ended and the seeds entered the stage of nutrient accumulation, during which the activities of antioxidant enzymes and endogenous hormones decreased gradually, and the content of nutrients increased gradually.