Comparative On Physiological Adaptation Of The Upland Rice And Rice In Dry Conditions

In dry conditions,the physiological index and photosynthetic rate of 13 upland rice and rice varieties were studied on seeding stage,flowering stage,filling stage and maturity stage,and did some correlated analysis with yield,hoped to find that the physiological index of impact of drought resistance and have some contribution to grow rice in dry conditions and cultivate drought resistance of the stronger varieties of upland rice.The research work conducted at experimental station of Jilin Agricultural University, Changchun city,Jilin province P.R.of China daring 2006 and 2007.They were divided into three types:upland rice,drought resistance of the stronger varieties,and drought resistance of the weaker varieties.Malondialdehyde content(MDA),the electrical conductivity,proline content,peroxidase activity(POD),superoxidase dismutase activity(SOD),catalase activity(CAT),chlorophyll content and photosynthetic rate were studied.The results showed:1) The yield was an important index sign of seed selection of upland rice.As different varieties of drought-resistant is different,Number of Panicles Per Square meters,number of grains Per Panicle,1000—grain weight of rice were lower than upland rice and drought stronger varieties.Thus yield lower than upland rice varieties in drought conditions.The average yield of upland rice is 5458Kg.hm~2;the average yield of drought resistance of the stronger rice varieties is 5400Kg.hm~2,the average yield of drought resistance of the weaker rice varieties in dry conditions.The yield of upland is the maximum.2) Chlorophyll content and photosynthetic rate of the three types varieties were increased from seeding stage to flowering stage,highest at the flowering stage,lower after that stage in dry conditions.As different drought-resistant,Chlorophyll content and photosynthetic of upland -rice was higher than rice in different stages.And there were very significant positive relationship between yield and photosynthetic rate.3) In dry conditions,ABA content of the three types of varieties was increased from seeding stage,highest at the maturity stage.ABA content of upland-rice was higher than rice on the seeding stage,the flowing stage and the filling stage.But ABA content of rice was higher than upland rice on maturity stage.4) In dry conditions,MDA content and the electrical conductivity in leaves of three types species were increased from seeding stage to maturity stage,highest at the maturity stage.MDA content and the electrical conductivity of rice were higher and upland rice was lower in the same stage.The differences between upland rice and the drought resistance of the weaker rice were very significant level.The activity of Superoxide dismutase(SOD),peroxidase(POD),catalase (CAT) was increased at first then lowered,higher at the flowering stage.The activity of Superoxide dismutase(SOD),peroxidase(POD),catalase(CAT) in upland rice was higher than rice.There were very significant differences between upland rice and the drought resistance of the weaker rice.5) In dry conditions,the content of proline in leaves of three types of species was lowed from seeding stage to flowering stage,was increased from flowering stage to filling stage,then lowed,highest at the filling stage.The content of proline of upland -rice was higher than rice on all stage;there were very significant differences between upland rice and the drought resistance of the weaker rice.There were very significant relationships between the content of praline and drought resistance of varieties.6) Through related analysis of physiological indicators and yield,the result showed that drought resistance of the stronger rice varieties could be grew in dry conditions,and as germplasm to cultivate varieties of upland rice.For this reason,we can save a lot of water resource,to improve the status quo of cultivation of rice in china.7) The result showed that:the activity of SOD,POD,CAT and the content of MDA,proline, the electrical conductance reveal the difference of physiological adaptation in different varieties. They could be selected as identification indexes for drought tolerance of rice and upland rice under dry conditions.