Biology Lab Report

Nematanthus nervosus

Average root ratings for each date data were collected. Root ratings were determined each week during the course of the experiment. Data was collected on 5 cuttings per treatment and averaged for each date. Root ratings were based on the scale of 0 to 5 rating, with 0 equaling no roots formed and 5 equaling a root mass equal to at least 50% of the shoot mass. (6 points)

Average root rating for Cuttings treated with Different Types of AuxinsControl ethanol 1000 ppm

IBA 50% EtOH1000 ppm

NAA 50% EtOH1000 ppm

2,4-D 50% EtOH1000 ppm IAA 50% EtOHOt 3/4/5 0 0 0 .4 .2 0

Oct 10/11/12 .4 1.4 .2 1.4 1 .9

Oct 17/18/19 1.6 2 2 4.2 1.4 2.4

Oct 24/25/26 2.8 2.4 2.8 4.6 4.4 2.6

Average root rating for Cuttings treated with Different Concentrations of Auxins Control 1000 ppm IBA talc 3000 ppm

IBA talc 8000 ppm

IBA talc 16000 ppm IBA talc

Oct 3/4/5 0 0 .2 .2 0

oct 10/11/12 0 .2 .2 1.4 0

oct 17/18/19 2.2 2.4 3.4 2.8 2.4

Oct 24/25/26* 3 3.4 4.6 5 4.2

Average root rating for Cuttings treated with Different Carriers of IBA

Control Ethanol 1000 ppm IBA

50% ethanol talc 1000 ppm IBA talc 1000 ppm IBA water

Oct 3/4/5 .2 0 0 0 .2 0

Oct 10/11/12 1.4 1.2 1.4 1.4 1.2 .8

Oct 17/18.19 2.2 1.8 2.4 1.8 1.8 1.2

Oct 24/25/26 2.4 1.8 3 2.2 2.6 2.6

*Only fill out this row if you made observations for this week

Written Results and Treatments:

Different Carriers:

1000 ppm IBA 50% ethanol (3)

1000 ppm IBA talc = 1000 ppm IBA water (2.6)

Control (2.4)

Talc (2.2)

Ethanol (1.8)

*In my section of the lab, the control and 1000 ppm IBA talc treated subjects were the first to show signs of callous growth, but in the weeks to follow, many of the other subjects including the control, ethanol, 1000 ppm IBA 50% ethanol, and 1000 ppm IBA water caught up quickly. Shortly after we started the lab, I noticed that many of the plants were infested with mealy bugs, most likely stunting the root growth process within all of the treatments. This most likely created difference in results compared to the other sections within the lab. None of the subjects quite got to the highest rating, but I do believe that the 1000 ppm IBA talc still would have gotten the highest ratings. There was no specific difference between the carriers in root growth site as they all seemed to grow thicker from the node at the surface of the sand while roots moved up and down the stem. The root growth process was pretty consistent between all of the different treatments, with some being more effective than others, but the 1000 ppm IBA 50% ethanol still coming out on top.

Type of Auxin:

1000 ppm NAA 50 EtOH (4.6)

1000 ppm 2,4-D 50% EtOH (4.4)

Control = 1000 ppm IBA 50% EtOH (2.8)

1000 ppm IAA 50% EtOH (2.6)

Ethanol (2.4)

**The 1000 ppm NAA 50% EtOH and 1000 ppm 2, 4-D 50% EtOH treated subjects were the first to show signs of callous growth as well as a few roots, but in the weeks to follow, the ethanol and 1000 ppm IAA 50% EtOH showed improvement in root growth as well. In the end, the 1000 ppm NAA 50% EtOH and 1000 ppm 2,4-D 50% EtOH treated subjects still came out on top. There was no specific difference between the carriers in root growth site as they all seemed to grow thicker from the node at the surface of the sand while roots moved up and down the stem.

IBA Concentration:

8000 ppm IBA in talc(5)

3000 ppm IBA in talc(4.6)

16000 ppm IBA talc (4.2)

1000 ppm IBA talc (3.4)

Control (3)

*The 3000 and 8000 ppm IBA talc treated subjects were the first to show signs of callous growth, but in the weeks to follow, the 1000 ppm IBA talc caught up to the 3000 ppm IBA talc callous wise, while the 8000 ppm IBA talc roots continued to grow along the stem and heavily from the node. In the end, there was no specific difference between the carriers in root growth site as they all seemed to grow thicker from the node at the surface of the sand while roots moved up and down the stem. The 8000 started out the strongest and was consistent throughout the entire study, while all treated subjects received a 5 and resulted in being the top choice of the entire lab.

DISCUSSION

Experiment 1.

In Experiment 1, the use of different types of auxins had different effects on the rooting systems of the herbaceous cuttings. For instance, 1000 ppm NAA 50 EtOH (4.6) auxin resulted to an increase in the rooting system and rate of growth. 1000 ppm 2, 4-D 50% EtOH (4.4) on the other hand results to a minimized rate of root growth. 1000 ppm IAA 50% EtOH (2.6) and Ethanol (2.4) on the other hand also affect the rooting system by initiating quick root formation as they act as additives that promote and enhance root growth. In conclusion, depending of the type auxins, root formation and development depend on the concentration of the auxins and the ethanol amount as well (Shen et al., 1988).

Shen, W. H., Petit, A., Guern, J., & Tempe, J. (1988). Hairy roots are more sensitive to auxin than normal roots. Proceedings of the National Academy of Sciences, 85(10), 3417-3421.

Experiment 2.

For experiment 2, the concentration of IBA had an effect on the rooting for herbaceous stem cuttings. However, the effect was jot significant and easily notable altogether. For instance, 3000 ppm IBA talc concentration resulted to a 4.6 rating. When compared to 8000 ppm IBA talc, which was at a rating of 5, it is evident that increased IBA concentration positively affects the root rating. However, there is a limit of the concentration upon which any ore concentration does not alter the root ratings for herbaceous stem cuttings. This is evident since 16000 ppm IBA talc concentration is more than the sample the previous sample but the rating is low at 4.2. In conclusion, increase in concentration increases the rooting for herbaceous stem cuttings but the concentration has a limit upon which any more concentration does not have an effect on the rooting for herbaceous stem cuttings (Pickett et al., 1990).

Pickett, F. B., Wilson, A. K., & Estelle, M. (1990). The aux1 mutation of Arabidopsis confers both auxin and ethylene resistance. Plant Physiology, 94(3), 1462-1466.

Experiment 3.

The use of different carriers of Auxin affects the rooting in herbaceous stem cuttings depending on the specific type of carriers used. For instance, 1000 ppm IBA 50% ethanol has a higher rating at 3 as compared to the other carriers. On the other hand, 1000 ppm IBA talc and 1000 ppm IBA water carriers are optimal at a rating of 2.6. This means that despite the carrier used, 1000 ppm IBA 50% ethanol is the best carrier to be used in the treatment process (Swarup et al., 2008).

Swarup, K., Benkova, E., Swarup, R., Casimiro, I., Peret, B., Yang, Y., & Levesque, M. P. (2008). The auxin influx carrier LAX3 promotes lateral root emergence. Nature cell biology, 10(8), 946-954.

Recommendation:

Experiment

Recommended Treatment

Average root rating for Cuttings treated with Different Types of Auxins. 1000 ppm NAA 50% EtOH (Because it has the highest rating of 4.6 from the experiment).

Average root rating for Cuttings treated with Different Concentrations of Auxins. 8000 ppm IBA talc (Because it has the highest rating of 5 from the experiment).

Average root rating for Cuttings treated with Different Carriers of IBA Plant Material. 1000 ppm IBA 50% ethanol (Because it has the highest rating of 3 from the experiment).

Common Name Latin Name

Zebrina Tradescantia zebrina

Goldfish Plant Nematanthus nervosus