8th INTERNATIONAL WHEAT CONFERENCE

IdeNTIfICATIoN of SouRCeS foR heAT, SALT, dRoughT
ANd fRoST ToLeRANCe IN SPRINg WheAT (TRITICum
AeSTIVum L.) geRmPLASm
Aziz ur Rehman, Nadeem Ahmad, M Arif Khan,
Makhdoom Hussain, NI Khan, M. Zulkiffal, W. Sabir,
Naeem Ahmad, M M Iqbal, M. Munir, M.Younis,
GM Subhani, MI Khokhar 1
1 Wheat Research Institute, AARI, Faisalabad-Pakistan
E-mail Address of presenting author: aziz_kml@yahoo.com, azizkamalia@gmail.com
Climate change is threatening the global wheat production. There is a dire need to develop
wheat varieties which can help improving wheat productivity by tolerating abiotic
stresses. Identification of sources for tolerance against all such stresses is a prerequisite
for development of wheat varieties capable of tolerating climatic hazards. Spring wheat
germplasm, comprising of about 450 entries from CIMMYT, ICARDA, Pakistan, India,
Bangladesh, Nepal, China etc., was evaluated for heat, salt, drought tolerance at Faisalabad,
Pakistan. The material was evaluated for heat tolerance during 2004-05 and 2005-
06 crop seasons. A set of germplasm was sown in a transparent plastic sheet tunnel and
another set was sown in an open field adjacent to the tunnel. The material was planted
on different sowing dates in November to ensure heading of all entries at the same time
(4 th week of Feb). The heat stress was imposed for 2 weeks just after heading in the 1 st year
and 4 weeks in the 2 nd year of study. The temp inside the Tunnel was maintained at about
5C higher than the open field. The data regarding ability to stay green, grains per spike,
1000 grain weight, yield per spike were recorded. The heat tolerance of an accession was
defined in terms of staying green for longer time under stress and better relative values
(stressed/non stressed) of the characters. The entries found the best were: MAYA/PVN;
BB#2/PT//CC/INIA/3/ALD’S’; WL711/3/KAL/BB//ALD’S’; WL711/CROW’S’//ALD#1/
CMH77A.917/3/HI666/PVN’S’
The same set of germplasm was evaluated for salinity tolerance at 10dS m -1 and 20dS m -1
levels by adding NaCl in aquaculture, wherein ½ strength Hoagland solution was used
as nutrition media. The data regarding root length, root weight, shoot length and shoot
weight were recorded from 3 weeks old seedlings grown under stressed and non stressed
(control) conditions. The relative values of the characters were used as selection criterion
for salt tolerance. The best 14 lines which showed the least effect of salinity on their
seedlings and 6 high yielding checks were evaluated in a RCBD trial with 6 replications.
Each variety/line was assigned a plot of 1.8m width and 5m length in salt affected field.
196