An Analysis of Growth Characteristics of Cotton Immature Fiber Mutant, im, Compared with its Near Isogenic wild type, TM‐1

Undergraduate #153
Discipline: Biological Sciences
Subcategory: Plant Research
Session: 4
Room: Exhibit Hall A

Evans Marrero - Xavier University Of Louisiana
Co-Author(s): Angela Nguyen, Xavier University of Louisiana Hee-Jin Kim, USDA Harish Ratnayaka, Xavier University Of Louisiana

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Fiber thickness, referred to as maturity, is a critical quality criterion in cotton industry. However, the plant growth and physiological processes that determine fiber maturity are not completely understood. An immature fiber mutant, im, with thinner fiber discovered in the early 1970’s and its near isogenic wildtype, TM‐1, provide a comparative model to understand how cotton fiber maturity is regulated, the knowledge required to improve fiber quality and yield. The mutation of the immature fiber variant is a 22 base pair deletion in a recessive pentatricopeptide gene that encodes for a mitochondrial-targeted transport protein with no known growth effects. We conducted a greenhouse study to determine if this mutation influences plant growth variables. The mutant had >4% less cotyledon width and 25% less height to cotyledons than TM-1 at 7 dap. However, cotyledon length and area remained the same in the two plant types at the same growth stage. During early reproductive age, biomass allocation was less to reproductive organs but more to roots in im than TM-1. However, the number of internodes and total plant height remained the same in the two plant types at the same growth stage. The thinner fiber mutation, therefore, affected the growth in a temporal fashion. Probable limitations in energy acquisition due to the effects of mutation on mitochondrial physiology appear to constrict the vegetative organs mainly during the early growth stages. Reproductive organs were affected later while the effects on vegetative growth was waning.

Funder Acknowledgement(s): Xavier University of Louisiana

Faculty Advisor: Harish Ratnayaka, hratnaya@xula.edu

Role: I planted and watered the plants used to collect data, used software to take measurements of leaves, cut the plants into different sections, dried the different parts, and weighed them, recorded and input data, and used software to analyze the data.