Assessment of mechanical damage in sweet corn seeds by image analysis

Transcription

1 UNIVERSITY OF SÃO PAULO Luiz de Queiroz College of Department of Crop Science Assessment of mechanical damage in sweet corn seeds by image analysis Francisco G GOMES-JUNIOR & Silvio M CICERO

2 Introduction 2

3 Image analysis X-ray test Precise and non-destructive method. Valuable procedure to evaluate mechanical damage in seeds. Objective In the present research, the efficiency of X-ray analysis in identifying mechanical damage in sweet corn seeds and its relationship with germination and vigor was evaluated. 3

4 Material and methods 4

5 Hybrid SWB 551 (sh2) Dow AgroSciences SHAPE: Spherical (S) and Flat (F) SIZE: Large (L), Medium (M1, M2 and M3) and Small (S) Seed classes: SL SM1 SM2 SS FL FM3 FS 1,000 seeds mass (g) Total 12,800 seeds Mechanical damage X-rayed (15kV, 300s) Germination Cold test 5

6 How the seeds were subjected to the mechanical damage? BC Impact Simulator Model 2000, DowAgroSciences Steel plate Hopper of input seed Opening to outside air Input compressed air 965 kpa Manometer Drawer removal of seeds Seeds were submitted to different levels of damage: 0, 1, 3, 5 and 7 impacts (five treatments) 6

7 Criteria for scoring mechanical damage in the embryo and endosperm of sweet corn seeds evaluated by X-ray test Embryo Score Endosperm Scor e Absence of damage 1 Absence of damage 1 Mechanical damage in the scutellum but no affect on the central area (non severe damage) 2 Little damage with no loss of the endosperm (non severe damage) 2 Damages in the plumule, coleoptile, central area of the scutellum, radicle or seminal root region (severe damage) 3 Loss of part of the endosperm (severe damage) 3 Example: Score 1.2 = absence of damage in the embryo and non severe damage in the endosperm. 7

8 Results 8

9 Description and occurrence (percentage) of the main types of mechanical damage observed by X-ray test in sweet corn seeds (sh2) submitted to mechanical damage Description of the damage Occur. * Example Loss or fracture of part of the endosperm, without reaching the embryonic axis and damage in the scutellum but not its central region (score 2.3) 0.98% Fig 1 Loss of part of the endosperm, without reaching the embryo (score 1.3) 0.73% Fig 2 Longitudinal fractures throughout the embryonic axis (score 3.2) 0.40% Fig 3, 4 and 5 Fractures throughout the seed reaching the embryo and endosperm (scores 3.2 and 3.3) 0.33% Fig 6 Fractures only in the endosperm, without reaching the scutellum (score 1.2) 0.30% Fig 7 Longitudinal seed fractures with loss of almost 50% of seed physical integrity (score 3.3) Loss of all or part of the radicle, reaching or not the base of the scutellum or endosperm (scores 3.1, 3.2 and 3.3) Transversal seed fractures (without the plumule or radicle parts) with loss of almost 50% of seed physical integrity (score 3.3) Fractures in the endosperm reaching the scutellum, however with no affect on the embryonic axis (score 2.2) 0.30% Fig % Fig % Fig % Fig 10 Diagonal fracture through the endosperm affecting the plumule (score 3.2) 0.09% Fig 11 Transversal fracture in the plumule without affecting the scutellum and 0.05% Fig 12 endosperm (score 3.1) * Occurence (percentage) based on 12,800 seeds submitted to mechanical damage. 9

10 Fig 12 X-ray image of sweet corn seed, FM3 class, thrown seven times against a metal plate (a) presenting severe damage in the embryo and no damage in the endosperm (score 3.1), resulting in abnormal seedling in the germination test (b) a 0.05% 10 b

11 Fig 11 X-ray image of sweet corn seed, FM3 class, thrown three times against a metal plate (a) presenting severe damage in the embryo and non severe damage in the endosperm (score 3.2), resulting in abnormal seedling in the germination test (b) a b 0.09% 11

12 Fig 10 X-ray image of sweet corn seed, FL class, thrown once against a metal plate (a) presenting non severe damage in the embryo and endosperm (score 2.2), resulting in normal seedling in the germination test (b) 0.17% a b 12

13 Fig 9 X-ray image of sweet corn seed, FM3 class, thrown once against a metal plate (a) presenting severe damage in the embryo and no damage in the endosperm (score 3.1), resulting in abnormal seedling in the germination test (b) seminal root a b 0.26% 13

14 Fig 8 X-ray images of sweet corn seed, FM3 class, thrown five (a) and three times (c) against a metal plate presenting severe damage in the embryo and endosperm (score 3.3), resulting in dead seed in the germination (b) and cold tests (d) a b c d 0.30% 0.24% 14

15 Description and occurrence (percentage) of the main types of mechanical damage observed by X-ray test in sweet corn seeds (sh2) submitted to mechanical damage Description of the damage Occur. * Example Loss or fracture of part of the endosperm, without reaching the embryonic axis and damage in the scutellum but not its central region (score 2.3) 0.98% Fig 1 Loss of part of the endosperm, without reaching the embryo (score 1.3) 0.73% Fig 2 Longitudinal fractures throughout the embryonic axis (score 3.2) 0.40% Fig 3, 4 and 5 Fractures throughout the seed reaching the embryo and endosperm (scores 3.2 and 3.3) 0.33% Fig 6 Fractures only in the endosperm, without reaching the scutellum (score 1.2) 0.30% Fig 7 Longitudinal seed fractures with loss of almost 50% of seed physical integrity (score 3.3) Loss of all or part of the radicle, reaching or not the base of the scutellum or endosperm (scores 3.1, 3.2 and 3.3) Transversal seed fractures (without the plumule or radicle parts) with loss of almost 50% of seed physical integrity (score 3.3) Fractures in the endosperm reaching the scutellum, however with no affect on the embryonic axis (score 2.2) 0.30% Fig % Fig % Fig % Fig 10 Diagonal fracture through the endosperm affecting the plumule (score 3.2) 0.09% Fig 11 Transversal fracture in the plumule without affecting the scutellum and endosperm (score 3.1) * Occurence (percentage) based on 12,800 seeds submitted to mechanical damage. 0.05% Fig 12 15

16 Fig 7 X-ray image of sweet corn seed, FL class, thrown seven times against a metal plate (a) with no mechanical damage in the embryo and non severe damage in the endosperm (score 1.2), resulting in normal seedling in the cold test (b) a 0.30% b 16

17 Fig 6 X-ray image of sweet corn seed, FL class, thrown seven times against a metal plate (a) presenting severe damage in the embryo and non severe damage in the endosperm (score 3.2), resulting in dead seed in the cold test (b) a 0.33% 17 b

18 Description and occurrence (percentage) of the main types of mechanical damage observed by X-ray test in sweet corn seeds (sh2) submitted to mechanical damage Description of the damage Occur. * Example Loss or fracture of part of the endosperm, without reaching the embryonic axis and damage in the scutellum but not its central region (score 2.3) 0.98% Fig 1 Loss of part of the endosperm, without reaching the embryo (score 1.3) 0.73% Fig 2 Longitudinal fractures throughout the embryonic axis (score 3.2) 0.40% Fig 3, 4 and 5 Fractures throughout the seed reaching the embryo and endosperm (scores 3.2 and 3.3) 0.33% Fig 6 Fractures only in the endosperm, without reaching the scutellum (score 1.2) 0.30% Fig 7 Longitudinal seed fractures with loss of almost 50% of seed physical integrity (score 3.3) Loss of all or part of the radicle, reaching or not the base of the scutellum or endosperm (scores 3.1, 3.2 and 3.3) Transversal seed fractures (without the plumule or radicle parts) with loss of almost 50% of seed physical integrity (score 3.3) Fractures in the endosperm reaching the scutellum, however with no affect on the embryonic axis (score 2.2) 0.30% Fig % Fig % Fig % Fig 10 Diagonal fracture through the endosperm affecting the plumule (score 3.2) 0.09% Fig 11 Transversal fracture in the plumule without affecting the scutellum and endosperm (score 3.1) * Occurence (percentage) based on 12,800 seeds submitted to mechanical damage. 0.05% Fig 12 18

19 Fig 3 Sweet corn seed, FL class, thrown once against a metal plate presenting external mechanical damage in the pericarp (a) and by X-ray test, severe damage in the embryonic axis and non severe damage in the endosperm (score 3.2) (b), resulting in abnormal seedling in the germination test (c) a b c 0.40% 19

20 Fig 4 X-ray image of sweet corn seed, FL class, thrown three times against a metal plate (a) presenting severe damage in the embryo and non severe damage in the endosperm (score 3.2), resulting in abnormal seedling in the cold test (b) 0.40% a b 20

21 Fig 5 X-ray image of sweet corn seed, FL class, thrown five times against a metal plate (a) presenting severe damage in the embryo and non severe damage in the endosperm (score 3.2), resulting in dead seed in the cold test (b) a 0.40% 21 b

22 Description and occurrence (percentage) of the main types of mechanical damage observed by X-ray test in sweet corn seeds (sh2) submitted to mechanical damage Description of the damage Occur. * Example Loss or fracture of part of the endosperm, without reaching the embryonic axis and damage in the scutellum but not its central region (score 2.3) 0.98% Fig 1 Loss of part of the endosperm, without reaching the embryo (score 1.3) 0.73% Fig 2 Longitudinal fractures throughout the embryonic axis (score 3.2) 0.40% Fig 3, 4 and 5 Fractures throughout the seed reaching the embryo and endosperm (scores 3.2 and 3.3) 0.33% Fig 6 Fractures only in the endosperm, without reaching the scutellum (score 1.2) 0.30% Fig 7 Longitudinal seed fractures with loss of almost 50% of seed physical integrity (score 3.3) Loss of all or part of the radicle, reaching or not the base of the scutellum or endosperm (scores 3.1, 3.2 and 3.3) Transversal seed fractures (without the plumule or radicle parts) with loss of almost 50% of seed physical integrity (score 3.3) Fractures in the endosperm reaching the scutellum, however with no affect on the embryonic axis (score 2.2) 0.30% Fig % Fig % Fig % Fig 10 Diagonal fracture through the endosperm affecting the plumule (score 3.2) 0.09% Fig 11 Transversal fracture in the plumule without affecting the scutellum and endosperm (score 3.1) * Occurence (percentage) based on 12,800 seeds submitted to mechanical damage. 0.05% Fig 12 22

23 Fig 2 X-ray images of sweet corn seed, FS class, thrown five times (a) and once (c) against a metal plate with no mechanical damage in the embryo and severe damage in the endosperm (score 1.3), resulting in normal seedling in the germination (b) and cold tests (d) 0.73% a b c d 23

24 Description and occurrence (percentage) of the main types of mechanical damage observed by X-ray test in sweet corn seeds (sh2) submitted to mechanical damage Description of the damage Occur. * Example Loss or fracture of part of the endosperm, without reaching the embryonic axis and damage in the scutellum but not its central region (score 2.3) 0.98% Fig 1 Loss of part of the endosperm, without reaching the embryo (score 1.3) 0.73% Fig 2 Longitudinal fractures throughout the embryonic axis (score 3.2) 0.40% Fig 3, 4 and 5 Fractures throughout the seed reaching the embryo and endosperm (scores 3.2 and 3.3) 0.33% Fig 6 Fractures only in the endosperm, without reaching the scutellum (score 1.2) 0.30% Fig 7 Longitudinal seed fractures with loss of almost 50% of seed physical integrity (score 3.3) Loss of all or part of the radicle, reaching or not the base of the scutellum or endosperm (scores 3.1, 3.2 and 3.3) Transversal seed fractures (without the plumule or radicle parts) with loss of almost 50% of seed physical integrity (score 3.3) Fractures in the endosperm reaching the scutellum, however with no affect on the embryonic axis (score 2.2) 0.30% Fig % Fig % Fig % Fig 10 Diagonal fracture through the endosperm affecting the plumule (score 3.2) 0.09% Fig 11 Transversal fracture in the plumule without affecting the scutellum and endosperm (score 3.1) * Occurence (percentage) based on 12,800 seeds submitted to mechanical damage. 0.05% Fig 12 24

25 Fig 1 X-ray image of sweet corn seed, FS class, thrown once against a metal plate (a) presenting non severe damage in the embryo and severe damage in the endosperm (score 2.3), resulting in normal seedling in the germination test (b) a b 0.98% 25

26 Conclusion 26

27 X-ray test is efficient in identifying mechanical damage in sweet corn seeds, allowing the establishment of a relationship between its occurrence and losses in germination and vigor. 27

28 Acknowlegments Fundação de Amparo à Pesquisa do Estado de São Paulo (São Paulo Research Foundation) Further information 28