Physiological Characteristics and Genetic Analysis on a Spotted-leaf Wheat Derived from Chemical Mutation

Characterization and Genetic Analysis of a Novel Light-Dependent Lesion Mimic Mutant, lm3, Showing Adult-Plant Resistance to Powdery Mildew in Common Wheat

“…The M66 lesion mutant obtained through X-ray mutagenesis expressed necrotic spots on the leaves at the young seedling stage with the main shoot and two or three tillers and continued to develop up to seed setting [ 65 ].The lesions in the HLP mutant, induced through ethyl methane sulfonate (EMS), only became evident on the leaf tips at the fifth or sixth leaf stage and randomly spread along the leaf blades, the leaf sheathes and flowering tissues; however these lesions were small (1–2 mm) and white in color [ 37 ]. The spotted-leaf mutant LF2010A was also obtained through EMS treatment; this mutant initially shows bright yellow spots on its primary leaves at the three-leaf stage, which subsequently spread to the leaves and leaf sheaths of the entire plant, including spike tissues [ 14 ]. The natural LM mutant in Ning7840 spontaneously exhibited small, discrete, yellowish spots only on the leaf blades around the heading stage [ 12 ].…”

“…The lesion-mimic phenotype became most obvious at the booting stage, progressively developing from the lower leaves to the flag leaf and characterizing discrete brown lesions on the leaf blades, leaf sheathes and flowering tissues [ 13 ]. Moreover, most of those LMMs are controlled by recessive genes [ 12 – 14 , 39 ], but only a few mutations are regulated by dominant genes [ 64 ]. In the present study, it could be concluded that the lm3 mutant had newly arisen because its LM phenotype was controlled by a partially dominant gene.…”

“…To reveal the function of LMs, numerous LMMs and their encoding genes have been identified from various plant species, such as Arabidopsis , rice, maize, barley and wheat [ 1 , 7 – 14 ]. In rice, spl7 (Spotted-leaf, spl ) was the first isolated spotted-leaf gene, encoding a heat stress transcription factor (HSF) protein, and spl7 lesions are induced in response to high temperature and ultraviolet solar irradiation [ 15 ].…”

“…Because of the complexity of the wheat genome and incomplete sequence information, only a few LMMs have been identified or mapped in wheat [ 12 – 14 , 37 ], the majority of which are invloved in pathogen resistance. The hypersensitive-like phenotype (HLP) mutant was obtained through a mutagenic treatment on the Argentine cultivar Sinvalocho M.A.…”

“…The observed lesions are light-dependent and have negative effects on subsequently developing traits and the enhanced expression of resistance to leaf rust [ 13 ]. In addition, the lesion symptoms of both AIM9 [ 39 ] and LF2010 [ 14 ] are controlled by a single recessive gene, and the total chlorophyll content and net photosynthetic rates of these plants are reduced with the onset of symptoms in the leaves. LF2010 is a light- and temperature- affected LMM, whose plant height, spike length, spike number per plant, grain weight per plant, grain number per spike, seed setting rate, and flag leaf length are lower compared with wildtype plants [ 14 ].…”