Fig 1.
Morphological structure and the regularity of flower and pod development in Chinese milk vetch.
These photographs were captured using a stereomicroscope (SZN-6 (45x), OPTIKA S.R.L., ITALY). The left panel illustrates the inflorescence layers (from bottom to top). The left bottom panel illustrates the inflorescence position of the inflorescence layers, and the inflorescences are numbered according to their positions relative to the rachis from most proximal to most distal. The panel on the upper right side illustrates the flower and pod developmental dynamics in three stages: the flower development stage (from the first appearance of the flower primordium to pollen maturity), flower and pod abortion stage (i.e., the fall-off stage of the flower and pod), and seed set stage (flower and pod develop into seed). The bottom right panel illustrates the processes of inflorescence development into seeds. The illustrations and photographs are not to scale; for reference, the flower widths are approximately 4.5 mm at pollen maturity, and the pod width and pod length are approximately 3 mm and 23 mm, respectively.
Table 1.
Relevant analysis of seed yield and seed-setting factors under spraying treatments (experiments 1 and 2).
Fig 2.
Relationships of dry matter accumulation with seed number and seed yield.
Relationship between seed number and dry matter accumulation amount (dry matter accumulation amount at early flowering or elongation to early flowering, in experiments 1 and 2; n = 180, A and B, respectively) and the relationship between seed yield and dry matter accumulation amount at full flowering (in experiments 1 and 2; n = 180, C) of Chinese milk vetch.
Fig 3.
Relationship between the dry matter and nitrogen accumulation in the inflorescence organs of Chinese milk vetch and the number of flowers and pods.
(A) Relationship between flower number and inflorescence dry weight of Chinese milk vetch (n = 180). (B) Relationship between flower number and inflorescence nitrogen accumulation in Chinese milk vetch (n = 180). (C) Relationship between pod number and inflorescence dry weight of Chinese milk vetch (n = 180). (D) Relationship between pod number and inflorescence nitrogen accumulation in Chinese milk vetch (n = 180). Orange symbols represent the squaring stage, and blue symbols represent the full flowering stage. All the experiments are shown.
Fig 4.
Relationships of seed number with dry matter, nitrogen accumulation and the proportion of nitrogen distribution in inflorescence organs, nitrogen accumulation in non-inflorescence organs in Chinese milk vetch.
Relationship between seed number and dry weight, nitrogen accumulation amount and nitrogen distribution rate in inflorescence organs of Chinese milk vetch (n = 180, A, B and D, respectively), and relationship between seed number and nitrogen accumulation amount in non-inflorescence organs of Chinese milk vetch (n = 180, C). Yellow symbols represent the squaring stage, and blue symbols represent the full flowering stage. All the experiments are shown.
Fig 5.
Relationship between dry matter translocation and seed yield of Chinese milk vetch.
(A) Relationship between seed yield and dry matter translocation amount of vegetative organs before flowering (Y = -0.0002X2 + 0.9483X – 93.309, R2 = 0.6382, P<0.001, n = 180). (B) Relationship between seed yield and dry matter translocation rate of vegetative organs before flowering (Y = -1.4937X2 + 108.78X – 1152.2, R2 = 0.7143, P<0.001, n = 180). (C) Relationship between seed yield and dry matter contribution rate of vegetative organs to seed yield before flowering (Y = -0.5781X2 + 47.142X – 105.53, R2 = 0.6833, P<0.001, n = 180). All the experiments are shown.
Fig 6.
Relationship between nitrogen translocation and seed yield of Chinese milk vetch.
(A) Relationship between seed yield and nitrogen translocation amount of vegetative organs before flowering (Y = -0.4571X2 + 71.665X – 1975.6, R2 = 0.494, P<0.001, n = 180). (B) Relationship between seed yield and nitrogen translocation rate of vegetative organs before flowering (Y = -0.5222X2 + 78.442X − 2140, R2 = 0.6498, P<0.001, n = 180). (C) Relationship between seed yield and nitrogen contribution rate of vegetative organs to seed yield before flowering (Y = -0.7965X2 + 133.45X – 4714.8, R2 = 0.6355, P<0.001, n = 180). All the experiments are shown.