**2.6 Maturity mutations**

### **2.6.1 Early and late**

214 Gamma Radiation

Plate 2. Plant habit mutants.

The early mutants were recorded in M2 with GR and GR + EMS. These mutants showed rapid growth and early maturity. Several workers like Dalvi (1990), Rudraswamy *et al*., (2006) and Bolbhat and Dhumal (2010) reported early and late mutants in horsegram.

In present investigation the early mutants of horsegram show pod maturity within 50-55 DAS in the gamma radiation and combination treatments. The agronomic traits like early flowering and pod maturity have bean always given paramount importance, while planning the breeding strategies. Gottschalk and Wolff (1983) explained the early mutants could be very much useful for genecological studies. The earliness was mainly achieved through rapid growth, during early stages of ontogeny and initiation of first inflorescence. Early maturity in the mutants may be due to the physiological, biochemical, enzymological and hormonal changes induced by the mutagens.

The late mutants were noted in M2 generation of horsegram with gamma radiation and GR + EMS. The main reason attributed to the late maturity were inadequate production of flowering hormones, physiological disturbances, enhanced production of a floral inhibitors and reduced ability to respond to the floral stimulus in the shoot apex (Beveridge and Murfet, 1996). According to Zakri and Jalani (1998) late or early maturity has agronomic significance as these mutants suit for the specific requirement of breeding strategy. The lateness in maturing is worthwhile for prolonging the vegetative phase and allowing the development of a strong sink, which may help to enhance the yield. In addition the period from flowering to maturity should also be long enough, for better seed filling. The late mutants were noted in horsegram with the treatments of gamma radiation and their combinations.
