I. Catalog Description

Agro 689, Special Topic in Molecular and Physiological Bases of Crop Improvement(3-0). Credit 3… (I) Tarpley. Plant molecular and physiological traits providing the bases for effective past and future crop improvements through traditional breeding, molecular breeding and biotechnology; the bases for genetic technologies for improvement of crops; and the bases for efficient germplasm screening procedures. Individual and collaborative critical consideration of diverse crops, and to adaptation and the ecology of yield, physiology of yield and quality, efficient use of agro-environmental resources, and the future of yield including new products. Web-enhanced. Prerequisites: MEPS 313 or equivalent; BICH 410; or approval of instructor. Cross-listed with MEPS 689.

II. Learning Objectives

After completing this course, learners will be able to:

III. Learning Activities:

This course is web-enhanced. Half of the meetings will be in the physical classroom (“in-classroom”), and half will be in a virtual or on-line classroom (a classroom that exists only at a web-site). The physical and on-line meetings will alternate weeks. By the second week of the course, the students will need adequate access to a computer for tasks such as word processing, access to the internet for tasks such as linking to particular web-sites, electronic submission of reports, and participation in on-line discussion groups. Students will also need familiarity with WebCT, which is software for on-line classrooms. Technical support for WebCT is provided by Texas A&M University.

(Percentage of class time for each learning activity follows in parentheses)

1. Instructor-directed in-classroom presentation or discussion of material (33%);
2. In-classroom group exercises (17%);
3. Instructor-directed on-line presentation or discussion of material (17%);
4. On-line group exercises and student-centered discussions (33%).

The course consists of seven two-week modules. For each module, the learner will need to complete the reading assignments beforehand. The instructor-directed in-classroom presentation or discussion is intended to provide explanation or clarification of the material. The in-classroom exercises are designed to stimulate and enhance learning through application of the material to particular situations. The instructor-directed on-line presentation or discussion is intended to (1) introduce issues and challenges of sub-topics that will not be covered through on-line group exercises and student-centered discussion, and (2) initiate, through expansive questions, the on-line group exercises and student-centered discussion topics. The on-line group exercises and student-centered discussions will be asynchronous, that is the learners are not required to be on-line at the same time. These exercises and discussions serve two purposes: (1) stimulate critical thinking in the subject content by the individual learners, and (2) provide a framework for collaborative learning in application of the subject material. The on-line exercises and discussions will be primarily conducted in the second half of a module.

IV. Course Outline

Part 1: Introduction to the course and the web-enhanced environment. Mechanics of the course. Sources for technology support. Sources for subject-content assistance. When and how to contact the instructor. Course objectives. Expectations. Introductions. Group establishment of participation standards. Introductory material. In-class small-group exercises based on introductory material followed by in-class discussion of results. Instructor-led discussion of the nature of asynchronous on-line discussion.

Part 2: Introduction to improvement of crop yield. Criteria of crop yield. Adaptation and the ecology of yield. Physiological basis of crop improvement. Utilizing information from several levels of biological organization. Separating causes and effects. Limiting factors, synergisms, and source/sink effects. Optimization and efficiency. Genetic and environmental influences on plants. Experimental approaches and quantitative methods. 

Module 2: Technologies for Crop Improvement                                                                                                 Top

Traditional methods. Marker-assisted breeding. Biotechnology. Advantages and disadvantages of the technologies using traditional breeding methods as the foundation.

Module 3: Adaptation and the Ecology of Yield.

Modification of environmental responses. Growing season, crop duration and yield. Adaptation to daylength. Adaptation to temperature. Adaptation to irradiance. Adaptation to water stress. Effects of latitide, solar radiation, temperature, rainfall. Physiological responses to temperature and climatic zones; Developmental responses to temperature, photoperiod, and light quality.

Module 4: Physiology of yield and product quality.                                                                                            Top

Regulation of photosynthesis by sink activity. Yield limitations by source and sink. Crop photosynthesis. Photosynthetic rate comparisons. Assessment of single leaf photosynthetic rate studies. Some component processes. Canopy photosynthesis and stand structure. Photorespiration. Dark respiration. Relative growth rate. Crop growth rate. Translocation and partitioning. Harvest index. Source of the rise in harvest index. Selection for harvest index. Hybrid vigor. Consideration of crop responses to environment in plant breeding.

Module 5: Efficient Use of Resources                                                                                                                  Top

Efficiency of fertilizer use. Other aspects of fertilizer use. Effects of irrigation on yield: efficiency and plant breeding implications. Crop protection. Efficiency and selectivity of insecticides and fungicides and relation to plant breeding for yield. Herbicides. Energy and crop production. Energy return ratios. Yield response to higher energy inputs. Crop transpiration and water relations. Crop adaptation to water-limited environments. Crop responses to salinity and other limiting soil conditions. Interaction of crop responses to pests and abiotic factors.

Module 6. Molecular and Physiological Bases of the Technologies for Crop Improvement.                    Top

This module builds on module 2, but moves from a description of the methods to a discussion of the manipulations, issues and challenges of the technologies. Genetic conservation. Hybridization. Apomixis. Developing mapping populations. Defining factors for identification of quantitative trait loci. Gene placement in genetic engineering. Genomes, proteomes, and metabolomes.

Module 7. Screening for molecular and physiological traits. The future of yield and product quality.       Top

Part 1. Screening for molecular and physiological traits. The use of crop physiology in defining traits for crop improvement. The need to quantify the value of specific traits for specific target production environments. The need for procedures for selecting and transferring traits that are efficient and reliable. Combination screening methods. Defining traits for screening. Emergent properties.

Part 2. The future of yield. Novel uses for staple crops. Product quality. New crops. Crops for energy. Bioproducts. Environmental change. Inputs. Phytoremediation.

V. Evaluation

400 total points:

321 – 360 = B;

281 – 320 = C;

241 – 280 = D;

240 or less = F.

                                                                                                                                                                                      Top

Three examinations (184 points):

34 point examination based on first two modules (during second week of third module).

75 point examination based on modules 3, 4 and 5 (during second week of sixth module).

75 point final examination weighted toward last two modules.                                                                      Top

Examination questions will be graded according to a rubric placing equal value on each question and equal value on the following eight criteria: 1) proposes important ideas relevant to question; 2) organized response; 3) potentially workable; 4) presented in sufficient and understandable detail; 5) demonstrates individual critical synthesis of ideas/information; 6) strong justification; 7) mentions potential pitfalls, alternate approaches; and 8) outsider with general scientific knowledge might be convinced.

Two reports (100 points):                                                                                                                                        Top

50 point individual reports. 3 pages. Report by individual as extension to small group case studies. The reports are individual efforts and provide a mechanism for students to expand their contribution or exploration in particular case studies or discussion topics encountered earlier in the course. The format of these concise reports is very specified as a mechanism to ensure that an unresolved question is carefully defined and then creatively, but rigorously, addressed.

Facilitation, summarization, and participation of on-line discussions (106 points):                                   Top

20 points for required facilitation of portion of on-line discussion. 16 points for required summarization of portion of on-line discussion. 70 points for participation in on-line discussion (10 points for each of 7 modules). The points will be based on both quantity and quality of postings. A grading rubric for evaluating facilitation and participation postings will be provided as an example by the instructor at the first meeting. The class will discuss and decide the rubric to be used during the course.

Small-group presentation (10 points): In-class presentations on module 6. Ten minutes per student organized as groups of three or four.