陆地棉遗传标准系TM-1的特性及其耐冷性

目的]通过系统调查TM-1农艺性状及纤维品质,研究芽期和苗期的耐冷性,以及对其在低温胁迫条件下的耐冷相关基因进行实时荧光定量分析,深入挖掘其耐冷机理,为该种质利用提供理论依据.方法]在田间,以中棉所35为对照,以人工调查方式对TM-1进行表型鉴定,依据国际校准棉花标准(HVICC)测定纤维品质,同时采用卡那霉素筛选...

Characteristics and Cold Tolerance of Upland Cotton Genetic Standard Line TM-1

【Objective】We systematically investigated the major agronomic traits and cold tolerance of accession TM-1 at the bud and seedling stages. The relative expressions of cold tolerance-related genes were analyzed by the qRT-PCR method. The cold tolerance mechanism of TM-1 was further discussed, which provides the theoretical basis for the breeding utilization of TM-1.【Method】The major agronomic traits of TM-1 were manually investigated in the field using variety CRI35 as the control. The fiber quality was assessed by an international calibrated cotton standard (HVICC), and the insect resistance (Bt) was detected by kanamycin screening and molecular detection technologies. For the cold tolerance testing, two contrasting accessions, cold-resistant accession Yu 2067 and cold-sensitive variety Hengmian 3 were set as controls, respectively. The cold resistance of TM-1 at bud stage and cotyledon stage was identified, treated at 4℃ and then recovered under normal conditions for 7 days, and the relative cotyledon spreading rate and the cold injury levels of plants were investigated, and cold injury indexes and cold resistance indexes were calculated. The portable chlorophyll meter was used for in vivo testing the leaf relative chlorophyll content (represented by SPAD value). The expressions of cold tolerance-related genes in leaves were measured by qRT-PCR method. 【Result】 The leaves of TM-1 were large and dark green. The pre-frost seed cotton yield was 2 791.50 kg·hm^-2, and the plant height was 94.60 cm. The growth period was about 135 days, and the yield, plant height, fruit branch number per plant, boll number per plant were higher than CRI35, while other agronomic traits were similar to CRI35. TM-1 had medium fiber quality. The test results of kanamycin and test paper showed that TM-1 did not contain the Bt like CRI35. Identification results of cold tolerance at bud stage showed that compared with the control treatment, the relative chlorophyll content and plant height of TM-1 decreased significantly. Low-temperature stress significantly inhibited hypocotyl elongation and chlorophyll synthesis in cotton leaves. Under low-temperature treatment, the taproots of TM-1 were damaged, but the lateral roots were more developed than those of the control. The cold tolerance level of TM-1 reached high cold resistance at the bud stage. Identification of cold tolerance at the cotyledon stage showed that the relative chlorophyll content and plant height of TM-1 decreased significantly compared with the control. The cold tolerance index of TM-1 at the cotyledon stage was 85.32%, which was significantly higher than Yu 2067, and the tolerance level of TM-1 reached cold resistance at the cotyledon stage. After the treatment of low-temperature stress for 24 h at the trefoil stage, nine genes were up-regulated in the TM-1 leaves, and their up-regulated expression folds were significantly higher than those of cold-sensitive accession. Dehydrin gene was up-regulated in TM-1 leaves, and the expression fold was similar to that in the leaves of Yu 2067, which was 4.69 times that in the leaves of Hengmian 3. The expression fold of the LEA3 gene in TM-1 leaves was significantly higher than that of Yu 2067 and Hengmian 3. 【Conclusion】 Accession TM-1 has stable agronomic characters and the medium fiber quality. It can be used as an ideal receptor for transferring exotic genes because without Bt. TM-1 can also be used as an important parent for cotton breeding and a gene source for cloning genes because of its good cold tolerance.