European Journal of Scientific Research - EuroJournals

Germination Studies in Selected Native Desert Plants of Kuwait 340
and Phragmites australis, soaking of seeds in GA3 solution for 24 hrs increased the
germination from germination by 64 and 86%, respectively. While hot water treatment
improved the germination in Asteragalus sieberri seeds, KNO3 was more effective than
heat treatment in increasing the germination of Citrullus colocynthis seeds.
Key words: Revegetation, propagation, biodiversity conservation, gibberellic acid,
stratification, seed dormancy
1. Introduction
Extreme aridity of the climate, over grazing, Gulf war activities and other human activities have led to
a significant loss of native vegetation cover, increased mobility of sand particles and the frequent
occurrences of dust storms in the Kuwaiti desert. Encroachment of agricultural lands, roads and other
infrastructure by wind blown sand has also become a serious problem in Kuwait (Abdulwahid, 1979;
Abolkhaire, 1981). Because the majority of native plants in Kuwait are annuals, uncertainties of
climate have a major influence on their germination, establishment, flowering and seed production.
The lack of sufficient native seed stocks has been the main bottleneck in all restoration programs in the
region including Kuwait (Peacock et al. 2003). Under normal conditions, seeds get buried in soil and
remain dormant for several years until sufficient amount of rainfall percolate into the soil to initiate
germination and new growth.
In nature, germination of fresh seeds in desert species is usually prevented by adverse climatic
conditions (drought and extreme temperatures). Hard seed coats and presence of high levels of growth
inhibitors also allow them to remain dormant during unfavorable growing conditions. Dormancy is
normally broken when seeds after they have absorbed sufficient moisture are exposed to mild
temperatures. The availability of sufficient moisture in the soil is also necessary to leach out growth
inhibitors present in the seed completely, a precondition to be fulfilled for successful germination
(Bryant, 1985).
Efficient propagation and establishment techniques that are crucial for both conservation of
native species and large-scale revegetation programs are currently not available. In view of these facts,
studies were conducted to determine the effects of seed treatments on germination in five main native
desert species (Cyperus conglomeratus, Citrullus colocynthis, Moltkiopsis ciliata, Astragalus sieberri
and Phragmits australis).
2. Materials and Methods
2.1. Climate and Soil of Kuwait
Geographically, Kuwait occupies approximately 17,800 km 2 of the northwestern part of the Arabian
Gulf, between 28º30’ and 30º05’N, and 46º33’ and 48º30’E It is bounded on the South by Saudi
Arabia, on the North and west by Iraq, and on the East by the Arabian Gulf.(Annual Statistical
Abstract, 1998). Kuwait’s climate is characterized by harsh summers and mild winters. Temperature
extremes are high, with means during the warmest and coolest months ranging between 46.2ºC and
6.9ºC (Annual Statistical Abstract, 1998). Winter brings occasional frost. Rainfall is minimal, not
exceeding 115 mmyr -1 , but evaporation is very high, averaging 14.1 mm.d -1 . The relative humidity is
low, and strong, dry and hot, northwesterly winds prevail during summer, particularly in June and July.
Kuwait’s soils are sandy in texture, alkaline, high in calcareous materials (CaCO3) and low in organic
matter and plant nutrients. Underground water resources are limited and brackish in nature with total
dissolved solids (TDS) concentrations ranging from 3.0 to 10.0 g.L -1 .