An Instituto Zootecnia/Sod Solutions/FUNDAG Agreement 

 

Activities Report 

 

Conducted by:

Instituto de Zootecnia (Animal Production Institute)

Instituto Agronômico (Agronomic Institute)

Agência Paulista de Tecnologia dos Agronegócios (Paulista Agency of Agribusiness Technology)

Secretaria de Agricultura e Abastecimento do Estado de São Paolo (São Paulo State Department of Agriculture and Supply)

Nova Odessa, January/2004

 

I – MOLECULAR FINGERPRINTING OF ORNAMENTAL GRASSES WITH RAPD MARKERS 

 

1. Introduction

The development of the chain reaction principle regarding the polymerase enzyme (PCR-Polymerase Chain Reaction) for nucleotide sequence analyses and later work by Williams, Welsh and McClelland, in 1990, revolutionized the studies on molecular markers. These authors described a method for identifying molecular polymorphism based on randomly amplifying fragments of DNA of different sizes through PCR, that is, RAPD (Random Amplified Polymorphic DNA). This technique has been widely used in studies of plant genetics, since it requires very little DNA, is more cost effective and is much simpler to work with than are other molecular marking techniques.

2. Obtaining RAPD Markers 

 

2.1. Study material

The following genotypes were analyzed in the present study:

 

1. Celebration

2. Dwarf

3. Tifsport

4. 419 (standard)

 

2.2. Extracting the DNA

Molecular fingerprinting was achieved by extracting DNA from young and healthy leaves collected at the Instituto de Zootecnia. The botanical material was obtained right before it was used. It was crushed with liquid nitrogen (N2) in a porcelain mortar. The extraction methodology was based on a protocol used by CIMMYT (Mexico), the main steps of which are described below:

1. Weigh 1.5g of crushed fabric in a 50 ml tube

2. Add 15 ml of a buffer solution (preheated with 0.1% of mercaptoethanol)

3. Incubate for 90 to 120 minutes in the shaker at 65°C

4. Remove the tubes, wait 15 minutes and then add 10 ml of isoamyl alcohol chloroform 24:1

5. Shake gently for 15 minutes

6. Centrifuge for 10 minutes at 3000 rpm (room temperature)

7. Transfer the upper portion to another tube containing 60ml of RNAse

8 . Incubate for 15 minutes at 37°C

9. Add 10 ml of isoamyl alcohol chloroform 24:1, shake for 5 min.

10. Centrifuge for 10 minutes at 3000 rpm

11. Recover the upper portion in another tube

12. Add the same volume of isopropyl alcohol

13. Collect (if possible) and recover the DNA in a 2.0 ml tube with 1.0 ml of TE

14. Centrifuge if unable to collect

15. Filter the propyl alcohol

16. Dissolve the precipitate with 1.0 ml of TE

17. Transfer to a 2.0 ml tube

18. Add 1.0 ml of phenol, shake

19. Centrifuge for 10 minutes at 1500 rpm

20. Transfer the upper portion to a new tube

21. Add 1.0 ml of isoamyl alcohol chloroform 24:1

22. Centrifuge for 10 minutes at 1500 rpm

23. Transfer the upper portion to a new tube

24. Precipitate the DNA adding 50 µ of NaCl 5M and 1.0 ml of propyl alcohol

25. Remove the precipitate with a hook (Pasteur pipette with a curved tip)

26. Wash the DNA with ethanol 70%

27. Centrifuge for 10 minutes at 3000 rpm

28. Dry at vac speed for 15 minutes

29. Suspend in 100 µ of TE

 

2.3. Checking the quantity and quality of DNA extracted

The yield and quality of the DNA extracted were achieved with an electrophoretic gel. After extracting the DNA, we prepared a 1% agarose gel and applied 5 µ of DNA solution diluted in a 1:10 proportion.

Following electrophoresis of the total DNA applied (2.5 V/cm), the gel was placed in a solution of ethidium bromide for 15 minutes and then submitted to UV light and photographed in a special apparatus, thus making it possible to analyze the quality and the quantity of DNA extracted.

2.4. RAPD Markers

Initial screening was performed to identify which primers offer the best amplification standard (bands of easy reading and of good amplification quality). The PCR reaction was conducted in a total volume of 25 µ containing 10 mM Tris-HCl, pH 8.3, 50 mM KCI, 1.5 mM MgCl2, 0.0001 gelatin, 10 hg of DNA, 1.0 µM primer, 100 µM of each dNTP and 1 unit of Taq polymerase. The DNA was amplified in a thermocycler (PCT-100 thermocycler – M.J. research, USA) at 95° for 5 min, followed by 42 cycles of 1 min at 94°C, 1 min at 36°C, 1.5 min at 72°C and a final stage of 7 min at 72°C. The product obtained was maintained at 4°C until analysis. The electrophoresis analysis consisted of depositing the amplified result in a 1.5% agarose gel, dipping in a TAE (Tris acetate EDTA) buffer and submitting to migration for approximately two hours (2.5 V/cm). It was then observed under UV light and a special apparatus, thus enabling analysis of the quality and the quantity of DNA extracted.

2.5. Statistical analysis of the data

Only the clearly amplified fragments were considered for data analysis. They were scored as being present (1) or absent (0), and were later used to calculate an index of genetic similarity between the genotype pairs analyzed (using the DICE index): SD= (2a/n-d), where a is the number of positive matches, n is the number of samples and d is the number of negative matches. A hierarchical classification of the samples was obtained from the DICE index using the UPGAMA (unweighted pair-group method using arithmetical averages) aggregation method. All the statistical analyses were conducted using the NTSYS-pc (Numerical Taxonomy and Multivariate Analysis System for personal computers, version 2.1) computer program.

3. Results and Conclusion

Once the conditions for obtaining a desirable profile of RAPD amplification were established, the next step was to differentiate the genotypes. Thirty different primers (Operon Technologies) were tested initially, eleven of which offered an amplification standard with bands of easy visual reading. These were retained for analysis of genetic differentiation of access sets. Figure 1 illustrates the RAPD amplification profile findings. Only polymorphic bands were retained for the statistical analyses – a total of 76. Figure 2 illustrates the dendogram (UPGMA) for Cynodon genotype differentiation (1- Celebration, 2- Dwarf, 3- Tifsport and 4- 419), constructed from the genetic similarities obtained by reading 76 RAPD bands. The Tifsport and 419 genotypes are very similar genetically (98.3% of genetic similarity), whereas Celebration has a 38%, 29% and 28% genetic similarity in relation to the Dwarf, Tifsport and 419 genotypes, respectively.

In conclusion, Celebration is clearly different from the other genotypes, as can be observed from the analyses using RAPD-type molecular markers, whereas Tifsport and 419 are practically composed of the same genetic material, considering that the small differences observed (1%) can be attributed to experimental errors.

 

II – PHYSIOLOGICAL EVALUATIONS

 

1. Average Height of the Plants

Right after transplanting the seedlings on Sept. 12 & 18/2003, as shown in Table 1, two observations were made of the height of all green house potted plants, comparing the different cultivars in terms of use or nonuse of limestone.

Table 1. Heights (cm) of the potted plants studied, comparing use of two doses of limestone (C1 nonuse of limestone and C2 2.0 t/ha), average for 4 repetitions

Evaluation Date

9/12/03

9/18/03

Liming

C1

C2

C1

C2

Celebration

8

7

8

8

Dwarf

9.5

10

10

10

Tifsport

9

9

10

10

419 (standard)

9

13

9

14

 

The Tifsport and Celebration cultivars showed no differences in relation to liming levels. On the other, the Dwarf cultivar showed a small difference between levels 1 and 2. There was also a difference recorded for cultivar 419. The greatest plant height was attained by Dwarf cultivar at level C1, and by cultivar 419 at level C2.

2. Number of Tillers

Table 2 shows the total number of erect tillers, of stolons and of tillers the in stolons, counted on different days.

According to Table 2, in relation to the erect tillers, the greatest number counted was in cultivar 419, followed by Tifsport, which was greater than Celebration, which, in turn, was greater than Dwarf (419>>Tifsport>Celebration>Dwarf). In relation to the number of stolons, Dwarf was found to have the greatest number of all the cultivars, followed closely by Celebration (Dwarf>Celebration>Tifsport>419).

The data shows that the Dwarf and Celebration cultivars are highly indicated for an effective coverage of the soil because they have a great number of stolons.

Cultivar 419 had a much greater number of erect tillers than the other cultivars tested.

As for the response to the different liming levels, Dwarf cultivar showed a lower number of erect tillers in the first three evaluations, and showed no difference for the number of tillers in the stolon.

Celebration cultivar showed a greater number of erect tillers in the first two evaluations, depending on liming levels. It also showed a greater number of stolons for the C2 limestone level. Tifsport and 419 showed a good response to limestone addition in relation to erect tillers.

Table 2. Number of erect tillers, of stolons and of tillers in the stolons, counted on the dates listed below, average for 4 repetitions

Evaluation Date

 

9/12/03

9/18/03

10/20/03

10/28/03

Liming

 

C1

C2

C1

C2

C1

C2

C1

C2

Dwarf

Erect tillers

10

7

14

12

25

18

14

18

 

Stolons

0

0

0

0

17

25

14

14

 

Tillers in Stolons

0

0

0

0

8

8

4

5

Celebration

Erect tillers

17

22

19

27

38

38

39

33

 

Stolons

0

0

0

0

20

22

9

19

 

Tillers in Stolons

0

0

0

0

9

9

3

3

Tifsport

Erect tillers

15

14

18

17

26

48

17

38

 

Stolons

0

0

0

0

15

22

9

8

 

Tillers in Stolons

0

0

0

0

9

6

3

3

419

Erect tillers

38

40

41

44

84

82

74

56

 

Stolons

0

0

0

0

14

12

10

10

 

Tillers in Stolons

0

0

0

0

6

6

4

3

C1 = without limestone, C2 = 2 tons of limestone/ha

 

3. Regrowth Speeds

Looking at the regrowth scores after the first cut, shown on Table 3, we can observe that cultivars 419 and Dwarf showed the quickest regrowth rates. We can also see that Tifsport has a very slow regrowth rate.

The cultivar showing the greatest difference in plant development after cutting, comparing treatment with and without limestone, was Tifsport, leading us to conclude that Tifsport development is more dependent on soil pH, i.e., it develops better in alkaline soils.

Another comparison between treatment with and without limestone shows that both cultivar 419 and Dwarf had slight slower regrowth rates when limestone was introduced, leading us to conclude that their development is less dependent on this soil corrective. This indicates their ability to form lawns requiring little maintenance.

Table 3. Evaluating plant regrowth in the green house experiment, seven days following the first cut

491

Scores

Scores

Scores

Average

 

E

M

V

 

C1B1

3

4

4

3.7

C2B1

3

4

3

3.3

C1B2

3.5

5

4

4.2

C2B2

3.5

4

3

3.5

C1B3

3

3

3

3.0

C2B3

2.5

3

3

2.8

C1B4

2.5

3

3

2.8

C2B4

3

3

3

3.0

Dwarf

Scores

Scores

Scores

Average

 

E

M

V

 

C1B1

2.5

4

4

3.5

C2B1

3

4

4

3.7

C1B2

2.5

4

4

3.5

C2B2

1.5

4

3

2.5

C1B3

2.5

3

3

3.2

C2B3

2.5

4

3

3.2

C1B4

3.5

4

3

3.5

C2B4

4

4

4

4.0

Celebration

Scores

Scores

Scores

Average

 

E

M

V

 

C1B1

2

3

3

2.7

C2B1

1.5

3

3

2.5

C1B2

1.5

2

2

1.8

C2B2

2

3

3

2.7

C1B3

2

3

2

2.3

C2B3

2

3

3

2.7

C1B4

2

2

2

2

C2B4

3

3

3

3.0

Tifsport

Scores

Scores

Scores

Average

 

E

M

V

 

C1B1

1

2

1

1.3

C2B1

2

3

3

2.7

C1B2

1

2

1

1.3

C2B2

2

2

2

2.0

C1B3

1

2

1

1.3

C2B3

3

3

2

2.7

C1B4

1.5

2

1

1.5

C2B4

1

2

1

1.3

Observations: C1= without limestone. C2= 22.0 t limestone/ha; B1, B2, B3 & B4 = blocks; E. M & V = evaluators.

 

III – DEVELOPING MORPHOLOGICAL DESCRIPTORS

To arrive at the morphological descriptors, the cultivars were planted in tubettes and maintained in green house conditions for the extent of the evaluations.

The morphological structures that were measured express the average taken from a hundred (100) measurements of these structures, using a ruler, caliper, and a stereoscopic microscope.

Only cultivar 419 was recorded as having flourished, but with an insufficient number of inflorescences for morphological evaluation. Therefore, this data will not be computed here.

CULTIVAR NAME: Celebration

1. PLANT: Growth pattern: Erect and stoloniferous.

2. PLANT: Average height: 9.8 cm.

3. LEAF: Position: Erect.

4. BLADE: Shape: Somewhat lanceolated.

5. BLADE: Pilosity: Sparse.

6. BLADE: Length (cm): 2.15 cm.

7. BLADE: Width (mm): 15.25 mm.

8. LEAF: Coloring: Green.

9. LIGULA: Size of hairs: Long and visible to the eye

10. LIGULA: Number of hairs: Large

11. LIGULA: Coloring: Transparent, with a dark red border.

12. STEM: Diameter (mm): 12.8 mm.

13. STEM: Length from the internode (cm): 1.4 cm.

14. AXILLARY AIR PROFILING: Intensity: Average.

15. STOLONS: Length (cm): 9.1 cm.

16. STOLONS: Shape: Cylindrical.

17. STOLONS: Coloring: Green with dark red spots, heterogeneous, with greater concentration of dark red pigmentation near the ligula.

 

CULTIVAR NAME: Dwarf 

 

1. PLANT: Growth pattern: Erect and stoloniferous.

2. PLANT: Average height: 7.4 cm.

3. LEAF: Position: Semi-erect.

4. BLADE: Shape: Lanceolated.

5. BLADE: Pilosity: Glabrous.

6. BLADE: Length (cm): 1.55 cm.

7. BLADE: Width (mm): 13.0 mm.

8. LEAF: Coloring: Dark Green.

9. LIGULA: Size of hairs: Long.

10. LIGULA: Number of hairs: Small.

11. LIGULA: Coloring: Transparent, with an uncolored border.

12. STEM: Diameter (mm): 5.7 mm.

13. STEM: Length from the internode (cm): 1.81 cm.

14. AXILLARY AIR PROFILING: Intensity: Small.

15. STOLONS: Length (cm): 5.6 cm.

16. STOLONS: Shape: Cylindrical.

17. STOLONS: Coloring: Dark red, with homogeneous coloring.

 

CULTIVAR NAME: Tifsport 

 

1. PLANT: Growth pattern: Erect and stoloniferous.

2. PLANT: Average height: 8.5 cm.

3. LEAF: Position: Erect to hanging.

4. BLADE: Shape: Lanceolated.

5. BLADE: Pilosity: Average.

6. BLADE: Length (cm): 2.59 cm.

7. BLADE: Width (mm): 11.0 mm.

8. LEAF: Coloring: Green.

9. LIGULA: Size of hairs: Small.

10. LIGULA: Number of hairs: Small.

11. LIGULA: Coloring: Transparent, with a dark red border.

12. STEM: Diameter (mm): 7.0 mm.

13. STEM: Length from the internode (cm): 2.20 cm.

14. AXILLARY AIR PROFILING: Intensity: Average.

15. STOLONS: Length (cm): 11.60 cm.

16. STOLONS: Shape: Cylindrical.

17. STOLONS: Coloring: Green spotted homogenously with dark red.

 

CULTIVAR NAME: 419 

 

1. PLANT: Growth pattern: Erect and stoloniferous.

2. PLANT: Average height: 26.75 cm.

3. LEAF: Position: Hanging.

4. BLADE: Shape: Long lanceolated.

5. BLADE: Pilosity: Small to average.

6. BLADE: Length (cm): 6.74 cm.

7. BLADE: Width (mm): 17.7 mm.

8. LEAF: Coloring: Green.

9. LIGULA: Size of hairs: Long.

10. LIGULA: Number of hairs: Average.

11. LIGULA: Coloring: Transparent, with uncolored borders.

12. STEM: Diameter (mm): 9.5 mm.

13. STEM: Length from the internode (cm): 4.3 cm.

14. AXILLARY AIR PROFILING: Intensity: Great, but with small emission of stolons.

15. STOLONS: Length (cm): 25.05 cm.

16. STOLONS: Shape: Cylindrical.

17. STOLONS: Coloring: Green spotted with dark red, heterogeneous, with greater concentration of dark red pigmentation near the ligula.

 

 

IV – AGRONOMICAL CHARACTERIZATION 

 

1. Material and Methods

The experiment was conducted in pots in a green house at the Insituto de Zootecnia, in Nova Odessa, state of São Paulo, from August to December 2003.

The soil used in the experiment belongs to the dystrophic Podsolic Red Yellow group. It was collected at a depth of 0 to 25 cm, dried in the shade, homogenized and sifted.

Samples for chemical analysis were taken from the dry soil. The results revealed: pH in CaCl2 = 4.1; M. O (g/dm3) = 20; P resin (mg/dm3) = 12; K (mmolc/dm3) = 0.6; Ca (mmolc/dm3) = 4; Mg (mmolc/dm3) = 1; H + Al (mmolc/dm3) = 47; SB (mmolc/dm3) = 5.6; CTC (mmolc/dm3) = 52.6 and V (%) = 11.

Cynodon dactylon grass was studied by testing the Celebration, Tifsport, Dwarf and 419 cultivars – 419 served as a comparative control.

The experimental outlining of randomly made blocks was used in a factorial scheme of 4 x 2, with four cultivars and two doses of limestone, involving 8 treatments with four repetitions, totaling 32 pots.

The limestone doses studied were (1) not corrected for soil acidity (zero dose), and (2) corrected by applying 2 tons of dolomitic limestone with 100% PRNT.

A quantity of 2.5 kg of prepared soil were placed in each ceramic pot, according to the description mentioned above, and after applying or not applying the limestone dose, the soil received distilled water up to field capacity, after which the pots were covered with plastic. The soil remained under incubation for 37 days.

In September 2003, a seedling from each cultivar was transplanted to corresponding pots, taking care to transplant homogeneous seedlings of each cultivar. Following this stage, plants were cut uniformly 5 cm from the soil surface. Then the pots received basic fertilizer, in the form of a diluted solution in the following amounts: 100 kg of P2O5/ha, 66 kg of K2O/ha, 30 kg of S/ha and 100 kg of N/ha.

After planting, and during the extent of the grass cultivation period, the pots were irrigated daily with distilled water in order to keep the soil close to field capacity.

The plants were cut twice. The first cut was performed at 40 days, after transplanting the seedlings, and the second cut, 40 days after the first cut, at which time the plants were cut level with the soil. Before the first cut, the number of basal tillers in the stolons was counted. After the first cut, the regrowth potential of each cultivar was evaluated using three assessment factors to which a score from 1 to 5 was attributed (1 = slow; 2 = average; 3 = medium; 4 = good; 5 = excellent).

All the material taken from the aerial portion of the first cut was submitted to further processing whereby the blades were separated from the stems and both were weighted separately to obtained the green mass. Then the blades and stems were placed in an oven separately for drying at 65°C, up to constant weight, weighed to obtain the dry mass of each component (to obtain blade/stem ratio) and the two figures were then combined to form the total dry mass per pot. After the second cut, the roots were separated from the aerial portion, washed and put to dry, and then weighed to obtain the dry root mass.

One day after the first cut, fertilizer replacement was carried out with an analytical reactant, applying an amount corresponding to 120 kg of ammonium sulfate/ha and 85 kg of K/ha.

The data was analyzed for variance, using the Dunnett test for comparison with the standard treatment for each cultivar studied, whereas the Tukey test (P<0.01%) was used to determine the effect of the limestone doses on the variables studied.

2. Discussion Results

The tables below show the results for several variables, together with the statistical relevance of these variables, the minimal significant differences and the variation coefficients, whereas the graphs show the individual variables that have no statistical relevance, but that nonetheless serve to determine the effect of each cultivar associated to the limestone dose.

The analysis of variance for total green and dry mass of both cuts showed significant differences (P<0.01) among the cultivars studied (Tables 1 and 2).

In both cuts, the Dwarf cultivar always showed the lowest total green and dry mass in relation to the Celebration and Tifsport cultivars, and also the 419 cultivar, used as a comparative control (P<0.01). However, Celebration cultivar was the most productive, thus differing from the other three cultivars (P<0.01), in both the first and the second cut, except for the first cut for dry total mass, where this cultivar showed production rates similar to (P>0.01) the other cultivars studied. The Tifsport cultivar did not differ (P>0.01) from the control cultivar (419), perhaps because its growth pattern is the most similar to that of cultivar 419 (Tables 1 and 2).

Table 1. Total blade and stem green mass (g/pot) at the first cut, and total green mass at the second cut, of four cultivars of Cynodon dactylon. Averages for four repetitions and two doses of limestone

Cultivars

Total green mass 1st cut

Blade green mass 1st cut

Stem green mass 1st cut

Total green mass 2nd cut

 

g/pot

419 (standard)

25.16

9.68

15.48

25.70

Celebration

29.87 **

6.09 **

23.79 **

33.35 **

Tifsport

27.71 ns

6.39 **

21.32 **

27.49 **

Dwarf

19.41 **

4.77 **

14.63 ns

22.08 **

DMS at 5%

4.25

0.80

4.17

1.75

CV. (%)

13.16

9.34

17.52

5.91

** and ns = treatments that deviate (P<0.01%) and treatments that do not deviate from the standard (P>0.01%), according to the Dunnett test, respectively

 

Celebration and Tifsport cultivars showed greater stem green mass than cultivar 419 (P<0.01), despite no dry mass difference (P>0.01) observed in comparison with the standard cultivar. All the cultivars showed greater stem mass than blade mass. This is the factor that most contributed to the total green and dry mass (Tables 1 and 2) composition, mainly in terms of Celebration, which has thicker and longer stems than the other three cultivars.

Celebration, Dwarf and Tifsport cultivars showed a lower blade/stem ratio (P<0.01) than cv. 419. Cultivar 419 showed an average 64% of stems whereas the figure for Tifsport and Dwarf cultivars was 75% and the figure for Celebration cultivar was 79%. The ratios for the four cultivars were considered low, indicating a greater presence of stolons. Even considering stolons as important for quick formation, soil coverage and lawn growth (leaving it less vulnerable to invasion by other undesirable plants), cultivars with a high percentage of leaf are preferable, mainly if we consider the ultimate use of these cultivars. However, it is known that the blade/stem ratio changes according to the cutting management procedure used. That is, the less it is cut, the higher the ratio. In this experiment, two cuts were made, but if three cuts had been made, within the same time interval, the blade/stem ratio may have been different, with leaves accounting for a greater percentage.

In relation to the regrowth rate evaluated after the first cut, Tifsport cultivar had the lowest potential (1.5), followed by Celebration (2.6) and both differed (P<0.01) from cultivar 419 (3.1). Dwarf was the cultivar with the best regrowth potential (3.5), but did not differ (P>0.01) from the control cultivar (419).

In relation to the dry mass of the root, cv. 419 showed the greatest mass (P<0.01), followed by Dwarf and Celebration cultivars, with intermediary masses, and finally by Tifsport, with the lowest mass (P<0.01) (Table 2).

Application of 2 tons of limestone/ha had a significant effect and benefit (P<0.01) on the variables: total green mass of the first and second cuts, and total dry mass of the second cut. Gains were observed of 13%, 13% and 9%, respectively, for total green mass of the 1st and 2nd cuts, and total dry mass of the 2nd cut, in comparison with treatment without applying limestone (Tables 3 and 4). This modest response to limestone application indicates that these plants are rustic, showing certain tolerance to acid conditions of the soil.

Table 3. Total green mass and blade & stem green mass (g/pot) at the first cut, and total green mass at the second cut, of four cultivars of Cynodon dactylon, following application of limestone doses. Averages for four repetitions and four cultivars

Limestone doses

Total green mass 1st cut

Blade green mass 1st cut

Stem green mass 1st cut

Total green mass 2nd cut

 

g/pot

No limestone

23.97

6.68 a

17.28 b

25.44 a

2 t/ha

27.10 a

6.79 a

20.32 a

28.87 b

DMS at 5%

2.47

4.17

0.80

1.18

CV. (%)

13.16

17.52

9.34

5.91

Averages followed by the same letter, in these columns, do not differ among each other (P>0.01), according to the Tukey test.

 

Table 4. Total dry mass and blade & stem dry mass (g/pot) at the first cut, and total dry mass and root dry mass at the second cut, of four cultivars of Cynodon dactylon, following application of limestone doses. Averages for four repetitions and four cultivars

Limestone doses

Total green mass 1st cut

Blade green mass 1st cut

Stem green mass 1st cut

Blade/stem ratio 1st cut

Total green mass 2nd cut

Root dry mass

 

g/pot

No limestone

8.35 a

2.33 a

6.02 a

0.43 a

10.62 a

8.3 a

2 t/ha

9.48 a

2.42 a

7.06 a

0.35 a

11.67 b

8.37 a

DMS at 5%

1.17

0.25

1.07

0.08

0.47

1.22

CV. (%)

17.91

14.26

22.28

28.61

5.84

19.94

The averages that followed by the same letter, in these columns, do not differ among each other (P>0.01), according to the Tukey test.

 

V – SUMMARY 

 

The different studies conducted reveal that: 

 

1. Tifsport and 419 cultivars have the same genetic material, considering that the small differences existing between them may be attributed to phenotype plasticity.

2. Tifsport and 419 cultivars also showed similar performance in agronomic tests.

3. Celebration cultivar proved to be clearly different from the others in terms of genetic characteristics.

4. In the agronomic and physiological tests, Celebration cultivar proved to be more productive than the others studied, showing a large number of stems and stolons, a characteristic that is of great interest in achieving quick and efficient lawn coverage.

5. As shown in the dendogram, Dwarf cultivar is genetically very similar to Celebration cultivar, considering that the morphological differences found could be attributed the phenotype plasticity of the species.

6. In the physiological tests, Dwarf and Celebration cultivars proved not to be very dependent on soil V%, showed better regrowth after cutting and quicker regrowth than the other cultivars studied. However, it also showed lower biomass production.

7. In the physiological tests, Dwarf and Celebration cultivars showed greater ability to provide effective soil coverage, because of their great number of stolons

8. Cultivar 419 (standard) and Dwarf showed the quickest regrowth rates in the physiological observations performed.

9. As for their requiring V%, 419 and Dwarf cultivars were the least dependent, and Tifsport responded to liming the most.

10. The slowest post-cut regrowth rate was observed for Tifsport.

 

 

Technical team:

Paulo Bardauil Alcântara – Instituto de Zootecnia

Valquíria de B. Gomes Alcântara – Instituto de Zootecnia

Márcia A. Cardelli de Lucena - Instituto de Zootecnia

Maria Tereza Colozza – Instituto de Zootecnia

Carlos Augusto Colombo – Instituto Agronômico

José Alfredo Usberti Filho – Instituto Agronômico

 

Support:

Valmir Antonio Barilon - Instituto de Zootecnia

Guilherme Dos Santos Diehl - Instituto de Zootecnia

José Carlos Vichesi - Instituto de Zootecnia

Antonio Tomáz - Instituto de Zootecnia

Sueli de Jesus - Instituto de Zootecnia

Fábio Augusto de Souza (FUNDAP/IZ Scholar)

 

Administrative Control and Data Entry:

Francie Erika Prado - Instituto de Zootecnia