Growth performance of some barley genotypes subjected to water stress at different growth stages

Other Title(s)

أداء النمو لبعض التراكيب الوراثية من الشعير المعرض للكرب المائي في المراحل المختلفة من نمو النبات

Dissertant

Haddadin, Maisaa Farah

Thesis advisor

Abd al-Ghani, Adil Hasan Mahmud
al-Majali, Nidal Faris

Comitee Members

al-Tarawinah, Khalid Ahmad Jafar
al-Samirrai, Abd al-Hamid Ahmad
Salamah, Nasir Muhammad

University

Mutah University

Faculty

Faculty of Agriculture

Department

Plant Production Department

University Country

Jordan

Degree

Master

Degree Date

2009

English Abstract

-Genetic variability of fourteen barley genotypes in response to drought was analyzed by imposing water stress at different growth stages of plant development.

The Fourteen barley genotypes include five locally registered barley cultivars (Rum, Acsad 176, Athroh, Yarmouk and Mua’ta) and one local check landrace in addition to eight released genotypes from International Center for Agricultural research in the Dry Areas (ICARDA) (Tadmor, Arta, Morocco9-75, WI2291, Zanbaka, Harmel, Furat2 and ER/Apm).

P o lyethylene glycol-6000 (PEG-6000) was used to induce water stress.

Genotypes were exposed at germination and seedling stages to two osmotic potential (OP) levels in addition to the control (i.e.

without PEG), mild osmotic potential (15% PEG-6000 with -0.72 Mpa OP, OP1) and severe osmotic potential (18 % PEG-6000 with -1.14 MPa OP, OP2).

ER/Apm genotype exhibited the highest germination rate, which could be advantageous over other varieties for drought adaptation at least at this stage of plant cycle.

Based on drought susceptibility index (DSI) for the five seedling attributes (coleoptile length, seminal root length, root fresh weight, shoot length and shoot fresh weight) under mild and severe water stress, genotypes could be ordered according to drought tolerance as follows: Morocco9-75, Yarmouk, Acsad 176, WI2291, Rum, ER/Apm, Athroh, Arta, Tadmor, Furat2, Muta’a, local landrace, Zanbaka and Harmel Barley genotypes were tested against four irrigation treatments imposed at different growth stages in addition to the control (continuous irrigation, T1).

The water stress treatments included sustain water stress (T2), early water stress (T3), late water stress (T4) and combination of early and late water stress (T5).

Results showed that water stress reduced grain yield.

Sustained drought stress treatment exhibited the highest reductions in grain yield and yield components while T3 showed the lowest reduction in comparison with the control treatment.

Two approaches were used to assess the level of drought tolerance at maturity stage; either by evaluating potential yield under water limiting environments or by assessing yield loss in response water stress treatments.

Based on the former approach, Athroh, Rum, ER/Apm, barley local landrace and Acsad 176 were the most tolerant genotypes because they exhibited high yield potential and high potential yield under non-limiting water and limiting water stress treatments, respectively.

While based on the later approach, W12291, Yarmouk and Zanbaka were the most tolerance genotype because they exhibited low to moderate reductions in grain yield in all limitingwater treatments (i.e.

low DSI).

Results revealed that yield potential (yield under TI) was positively correlated with potential yield and yield losses under limiting water environments, indicating that yield losses were more for genotypes with high yield potential than those exhibited low yield potentials.

Water stress significantly decreased leaves chlorophyll content and relative water content (RWC) but increased proline level in leaves.

In conclusion, results revealed high level of variability in the level of drought tolerance among the 14 tested barley genotypes.

Similar drought tolerance rank was observed in WI2291 and Yarmouk at different growth stages, while Athroh characterized by high yield potential and high potential yield under non-limiting water and limiting water stress treatments.

In consequence, these genotypes could be considered as a potential source of genes for drought tolerance.

Main Subjects

Botany

Topics

• Barley

No. of Pages

89

Table of Contents

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-304840