Abstract Stem rust caused by Puccinia graminis f. sp. tritici is a destructive wheat disease worldwide, traditionally controlled by the Sr31 resistance gene for many years until the virulent strain; Ug99 emerged in 1999. The new pathotype threatened the global wheat production, and was later detected in Hamedan and Lorestan provinces of Iran. To tackle this disease, it is necessary to find new sources of resistance against the Ug99 race and its variants. Ninety-five Iranian wheat genotypes were analyzed for the presence of the stem rust resistance genes; Sr2, Sr22, Sr24, Sr25 and Sr31 with the help of several CAPS, STS and SSR markers. Seeds of the tested genotypes and Thatcher as negative control and five isolines as positive controls were sown in pots in a greenhouse. After DNA extraction, polymerase chain reaction (PCR) was performed using primers for the corresponding markers. The Iag95 marker demonstrated the presence of Sr31 in 10 genotypes. Nine genotypes showing the Gb associated band, carried Sr25. J09, the linked marker with Sr24, detected this gene in only two genotypes. No genotype showed the bands for markers linked to Sr2 or Sr22 genes. The combined presence of Sr24 and Sr31 was identified in six genotypes. So far, neither Ug99 nor its variants have virulence for Sr2, Sr22 and Sr25 suggesting they could be transferred from donor sources to suitable lines for commercial uses.
Mercy Odemba, James Owuoche, Michael Okiror, Ruth Wanyera Egerton University, Egerton, Kenya Kenya Agricultural and Livestock Research Organization, Private Bag, Njoro, Kenya Key words: Stem rust, Seedling resistance, Adult plant resistance, Races
Stem rust races Ug99 and its variants are virulent to a large number of resistant genes present in the widely grown wheat (Triticum aestivum L.) cultivars. This study was conducted to evaluate seedling and adult plant reaction to four stem rust races TTKSK, TTKST, TTKTK and TTTSK in CIMMYT wheat lines. The evaluation was conducted in the greenhouse with the adult plant resistance experiment conducted in a randomized complete block design (RCBD). Out of the 39 lines evaluated, only SRG21, SRG34 and SRG39 showed a reaction of 3 to race TTKST, SRG22 exhibited a reaction of 3 to race TTKTK, SRG25, SRG32, SRG36 and SRG37 displayed a reaction of 3 to race TTKSK and SRG27 and SRG39 showed a reaction of 3 to race TTTSK the rest revealed infection types of between 0 and 2.
Yea.. Not good. We have breed wheat strains that usually can resist all sorts of diseases, but recently there has been a revival of Stem Rust. Its a fungi that around 90% of wheat is susceptible to.
Hopefully plant breeders can figure this one out before it has some drastic impacts on the global food industry.
"Challenge yourself to get out of your comfort zone!"
Dr. Maricelis Acevedo works at North Dakota State University, where she studies rust pathogen virulence evolution and the utilization of host resistance to manage cereal rusts. Her work is part of the Borlaug Global Rust Initiative, an international consortium working on wheat rust research and enhancement of wheat productivity worldwide.
Can you tell me a little about you? For example, how did you become interested in science?
I was born and grew up In Puerto Rico. I have two sisters (I am a middle child). My mom was a social worker and ran a child care centre for low-income families. My dad was an agronomist at an agricultural experiment station of the University of Puerto Rico. While my sister and I were kids, my dad was working on his master’s degree and many of the Sunday family trips ended at the research station fields and laboratories. One of my most vivid childhood memories is waking up in the middle of the night and sneaking out of my room to check on my dad who was working on his stats homework at the dining table. My grandparents on my mom’s side of the family and my dad’s family both have small farms. As far as I can remember, I was always interested in science from a research point of view. I remember playing to be a medicine doctor and an agronomist as a kid.
What has been your career path? What drives you and makes you enjoy your current work position? What keeps you motivated when everything seems to fall apart?
I went to the University of Puerto Rico-Mayaguez where I got a bachelor’s degree in Biology then a Masters in Agronomy in the area of Crop Improvement. I was working on common bean resistance to virus. Since my master’s project was on genetics of disease resistance I decided to get a PhD in Biology with a specialization in Plant
Pathology at the University of Nebraska-Lincoln. My thesis project studied the virulence diversity of the bean rust pathogen and its co-evolution with wild beans in Honduras.
Before finishing my degree, I was offered a postdoctoral research appointment with the USA Department Agriculture in Aberdeen, Idaho where I began my career on cereal rust diseases, including some work on Ug99 resistance. Stem rust races of the Ug99 group are virulent on most of the current wheat varieties worldwide and are a major threat in Africa. This got my foot in the door of the international community working in East Africa for identification and utilization of new sources of resistance to combat this pathogen.
In 2010 I accepted a tenure track faculty position as a wheat rust pathologist at North Dakota State University. In this position I get the opportunity to manage a research program, mentor graduate students and teach. One of the most enjoyable aspects of my position is to mentor students and provide leadership to the junior researchers in my program. I enjoy when new projects are born during an informal conversation with my students; sometimes I provide the initial idea but often, they bring a question or a concern and a new project is born! Moreover, the best moments so far have been those moments when the students or myself finally figure out the answer to a research questions; the ta-da moments!
What have been the biggest struggles you have had to deal with on your journey? In particular, have you faced discrimination or felt disadvantaged? How have you dealt with these issues?
I have not felt discriminated against. However, I have struggled with the fact that in many circles women in science are being considered a necessary “quota”. Being a Hispanic female in science, I sometimes worry that I am seen as somebody that is just going to make you look on the group minority counts.
Then sometimes without any particular reason, I question my role or my capability, I question the fact that I have been selected because I am an expert on a particular subject. So far I have made sure I feel comfortable with my role in a particular group. If I feel I am just used a “quota”, I reject the offer to belong to that group or I discuss my role to make sure my opinion is actually being sought. Under all circumstances, I do my best.
What is the (professional/personal) achievement you are the most proud of?
So far the personal achievement I feel the most proud of is to be able to have come this far in my professional career without losing touch with my family in Puerto Rico, making time for a personal life and staying physically and emotionally healthy despite the demands of my job.
On the professional side of things, I feel very proud that my science research reflects my social values. I feel proud that ultimately the science I work on will end up in the farmers’ fields. I have always committed to projects that could be applied/used by farmers or would impact yield protection to ensure food security and better utilization of inputs (such as fungicides).
If you could (or if you had to) start over again, what would you do differently?
If I could go back to my graduate school years or even post-doc years, I would have spent more time learning about and getting involved with transfer of technology and knowledge from the scientists to the policy makers and the general public. I would have sought opportunities to get training in policy making, international agriculture, and international development.
I really think a lot of good science never sees the “daylight” because scientists don’t/can’t communicate effectively to the public their knowledge and the importance of their discoveries. Moreover, I think more scientists should be involved in communication with the public and the media. This would help preventing misinformation and improve the perception of science-based practices that could improve people’s lives.
What would you like to tell your PhD self?
Don’t forget what you are passionate about. Remember why you chose this career path!
Have mentors played an important role in your career? Are you yourself acting as a mentor?
My master’s degree and PhD advisors both taught me the importance of doing science that impacts and can improve people’s life especially in the developing countries.
Over the past five years, I have mentored several graduate students as a thesis supervisor or as part of a thesis committee. Closest to my heart is mentoring the four graduate students in my laboratory. It’s a great responsibility and I don’t take it lightly.
What has been the most important advice you were ever given?
An emeritus professor once told me to follow my heart about my career path. And so I did!
What is the best advice you could give to young female scientists?
Challenge yourself to get out of your comfort zone, be part of the conversation!
Self-confidence is not always easy to build. How have you dealt with confidence issues? Do you have tips/tricks that helped you with establishing yourself as a leader in your field?
You can learn a lot about your career path by talking and spending time with senior scientists that you admire not only as a scientist but also as a person. You will learn what it takes to “survive “and succeed but it will also teach you that these scientists you admire have fears and concerns just like you. They have failed many times before they reach the point they currently are.
It is important to take part (no matter if that is just to seat at a meeting) on administrative/professional committees and learn the ins and outs at an early stage. The way I look at it is the more you know, the less you fear!
Work/life balance is one of the big issues women face. How do you deal with this issue? Do you have any tips that helped you?
I believe in having a friend or a partner that I feel completely comfortable asking for help when I need it. I also strongly believe in picking my battles and my chores and outsource/ get the most of the system to better utilize my time. I go grocery shopping online (I sometimes order my groceries while waiting at the airport), pay my bills electronically, listen to audiobooks, have the shortest commutes I can, use apps to stay organized and keep track of deadlines. These are all small things that help me.
Surround yourself with a support network (other females and males) from different aspects of your life (work and outside of work), people who understand your situation and can be supportive. If you can afford it, use professional services so that you can dedicate more time to the essentials such as family and friends. This also helps to find time to stay healthy (cooking at home, exercising and spending time with/for yourself).
What are, for you, the main initiatives that need to be taken to improve gender equity? What would you like to see happening in the next ten years or so?
I hope to get past the 20:80% female: male ratio at work so that we can be seen as professionals or scientists, etc. and not as female scientists, etc. Equal pay for equal jobs must be the norm. I would also like to see flexible schedules and day care on site as part of the new norm at work so the families are welcome. By doing so, there will be no need to choose between being a professional or looking after your kids so that people can have emotionally healthy families.
And to finish, fortune cookie question! Is there a little something on your desk/bench that you have carried with you from lab to lab as a kind of talisman? What is it?
A satellite image (from Google Earth) of my family farm in Puerto Rico!
