FERTILITY EXPRESSION OF PHOTOPERIODTEMPERATURE-SENSITIVE GENIC MALE-STERILERICE IN GUANGZHOU AND THEIR RESPONSE TOPHOTOPERIOD AND TEMPERATURE TREATMENTS A PRELIMILARY STUDY ON THE RELATIONSHIP BETWEEN HEAT SHOCK RESPONSE AND POLLEN FERTILITY TRANSFORMATION OF A CYTOPLASMIC MALE STERILE LINE OF RICE(ORYZA STIVA) Effect of Methylglyoxal- bis (Guanylhydrazone) Treatment on Polyamine Contents of Photosensitive Genic Male Sterile Rice and Its Relationship with Fertility Transformation