Effect of Crossing on Physiological Quality of Hybrid Corn (Zea mays L.) Seed

Abstract

Seed physiological quality is an important factor in farmer acceptance of a hybrid variety. High physiological quality can be an added value to agronomic advantage of hybrid variety that consist of single cross, double cross, and three-way cross. The aim of this research was to investigate whether type of crossing affect the physiological quality of the hybrid corn seed. Four corn purelines each of high germination lines (BS07 and BS30) and low germination lines (BS32 and BS50) was planted. Completely randomized design with four replications was employed to perform 2 double cross, 8 three-way cross, and 10 single cross. Seed physiological quality was evaluated based on vigor index, germination percentage, storability, germination speed, uniformity of germination, ten normal seedlings dry weight, plumule length, primary root length, and number of seminal root. T-student and analysis of varians were used to analize the effect of maternal and crossing type on physiological quality of produced hybrid seed. The results showed that the maternal effect on physiological quality was depended on parents combination. Storability, ten normal seedlings dry weight, and primary root length were not affected by maternal effect, whereas other variables were affected on at least a pair of parents. Parent seed physiological quality significantly affected to its hybrid seed physiological quality. The effect was present on single cross and three-way cross hybrids. Low physiological quality seed parent produced low physiological quality hybrid seed. In single cross, crossing of two high physiological quality parents or crossing of high and low quality parents produced high physiological quality hybrid seeds. However, crossing of two low physiological quality parents produced low physiological hybrid seed. In three-way cross, crossing of parents that consist of at least one high physiological quality line produced a higher physiological quality hybrid seed than hybrid seed of three low physiological quality parents. In double cross, crossing of high and low physiological quality F1 parents with its reciprocal crossing produced not different physiological quality hybrid seed.