Study On Drought Tolerance Of Tomato Introgression Lines From Wild Species In Solanum Pennellii.

Drought is one of the major abiotic stress factor affecting the normal metabolism, growth and development of plants,which have a serious influence on agricultural development in China.Current development of molecular quantitative genetics has provided an effective approach to study the genetic mechanism of drought tolerance and its genetic patterns for complex quantitative traits in tomato(Lycopersicun esculentum).Therefore,it has an important significance to map chromosome and to dissect genetic factors for complex quantitative traits associated with drought tolerance in tomato molecular breeding of drought tolerance.In this study,tomato processing cultival M82 and Lycopersicon pennellii introgression line groups contained 45 introgression segments were used as materials, and the treatments of drought stress and dealing with normal watering were carried out for all the materials with the method of water control in pots.Two biological characteristics(plant height and leaf area) and four physiological characteristics (proline content,MDA content,soluble sugar and soluble protein content),which were closely related to the drought tolerance of plant,were investigated and analyzed for the treatments and control groups,respectively.The results were as follow:(1) Under normal condition,the plant height and leaf area will be inhibited by the drought stress.In this study,compared with the two biological characteristics(plant height and leaf area) between the control and the treatments of drought stress,the results indicated that the growth of plant height and leaf area of plants contained introgression segments IL3-1,IL4-3,IL5-1,IL9-2-6,IL11-2,IL12-2,IL12-3 and IL 12-4 were not inhibited under drought stress,but promoted.(2) Under drought stress,the proline content,MDA content,soluble sugar and soluble protein content are generally increased.In this study,compared with the four physiological characteristics(proline content,MDA content,soluble sugar and soluble protein content) between the control and the treatments of drought stress,the results indicated that the proline content,MDA content,soluble sugar and soluble protein content of plants contained introgression segments IL1-1-3,IL1-2,IL1-3,IL1-4, IL2-3,IL2-5,IL2-6,IL3-1,IL3-4,IL3-5,IL4-1,IL4-2,IL4-3,IL5-3,IL5-4,IL5-5, IL6-1,IL6-3,IL7-1,IL7-2,IL7-4,IL8-1-1,IL8-2,IL8-3,IL9-1,IL9-2-6,IL10-1, IL10-2,IL10-3,IL11-1,IL11-2,IL11-3,IL11-4,IL12-2,IL12-3,IL12-4 were decreased.In these plants,some showed the abnormal phenomenon in one index,and some showed the abnormal phenomenon in more than two indexes.(3) Compared with the 45 introgression segments and parent M82,the results indicated that 23 regions(such as 1-A) on 12 chromosomes of tomato appeared only one marker in the analysis of six indexes.It is possible that the character locuses related the drough tolerance may be appear in these regions.(4) 21 regions(such as 1-F) on 12 chromosomes of tomato appeared two markers in the analysis of six indexes,and 19 regions(such as 3-A) on 12 chromosomes of tomato appeared three markers in the analysis of six indexes.It is possible that some character locuses related the drough tolerance may be also appear in these regions.(5) 14 regions(such as 2-E) on 12 chromosomes of tomato appeared four markers in the analysis of six indexes.It is possible that some character locuses related the drough tolerance may be also appear in these regions.(6) In the analysis of six indexes,9 regions on 12 chromosomes of tomato appeared more than five markers.In these regions,5-F,5-H,11-D and 11-F were appeared five markers,which were mainly concentrated on the 5th and the 11th chromosome.11-B on the 11th chromosome and 12-D,12-E,12-G on the 12th chromosome were appeared seven markers.Therefore,the 2th,the 5th,the 11th and 12th chromosome must be noted.(7) Through carrying on the relevant analysis of the six indexes closely related to drought tolerance characteristics,the results indicated that there were no remarkable relevance between the plant height and leaf area under the condition of sufficient moisture content.However,under the condition of drough stress,there were significant relevance between the plant height and leaf area.(8) Under the condition of sufficient moisture content,there were no relevance among the proline content,MDA content,soluble sugar and soluble protein content. However,under the condition of drough stress,there existed positive and negative relevance between the proline content and the soluble sugar,soluble protein content.