**7. Breeding for drought resistance — Conventional approach**

Selection in the target habitat has been the standard way of breeding for drought resistance across crops. Over the past decade several OPVs and Hybrids have been developed with the active participation of the national programs across the target countries (Table. 3). Grain yield and other shoot traits has been the focus in most of their projects. This is a typical case of plant breeding. Selection for a plant's performance would have been better understood and most effective selection would have resulted probably by using root characters in the parental selection and breeding program.

In rice, an innovative strategy was adapted to breed for drought resistance. The donor for char‐ acteristic deep root was a local variety Budda. The donor for grain yield was IR-64. The genera‐ tions were advanced by raising the families derived from F3 onwards in farmers' fields and involving farmers in the selection process. Each of the F3 families was divided into two parts with one being directly sown and maintained under well-watered conditions, while the other one was maintained under drought stress. Water was provided to each one (WW and LMS) by precise measurements. While WW set received 80 % of the water lost due to evaporation, the other one (Stress) received 60 % of water evaporated (Evaporation was measured by in instal‐ ling and maintaining a pan-evaporimeter in the field). Data was recorded on grain yield and bi‐ omass at harvest. Selection at each generation was based only on biomass. High biomass types under both conditions were forwarded to next generation. In the next generation, one tiller from each plant was grown in PVC pipes to study root traits (Figure 3). All subsequent generations were forwarded in three places. Two in field (WW and drought) and one in PVC tubes. The se‐ lection was based on all three traits: Good Roots + Shoots + Grain yield [21].

**Figure 3.** Manifestation of transgressive segregation for root traits in rice.

Several varieties have been developed in different countries adopting conventional plant breeding principles (Table 3). Some of these have been accomplished using markers and some without.

**7. Breeding for drought resistance — Conventional approach**

lection was based on all three traits: Good Roots + Shoots + Grain yield [21].

**Figure 3.** Manifestation of transgressive segregation for root traits in rice.

selection and breeding program.

160 Plant Breeding from Laboratories to Fields

Selection in the target habitat has been the standard way of breeding for drought resistance across crops. Over the past decade several OPVs and Hybrids have been developed with the active participation of the national programs across the target countries (Table. 3). Grain yield and other shoot traits has been the focus in most of their projects. This is a typical case of plant breeding. Selection for a plant's performance would have been better understood and most effective selection would have resulted probably by using root characters in the parental

In rice, an innovative strategy was adapted to breed for drought resistance. The donor for char‐ acteristic deep root was a local variety Budda. The donor for grain yield was IR-64. The genera‐ tions were advanced by raising the families derived from F3 onwards in farmers' fields and involving farmers in the selection process. Each of the F3 families was divided into two parts with one being directly sown and maintained under well-watered conditions, while the other one was maintained under drought stress. Water was provided to each one (WW and LMS) by precise measurements. While WW set received 80 % of the water lost due to evaporation, the other one (Stress) received 60 % of water evaporated (Evaporation was measured by in instal‐ ling and maintaining a pan-evaporimeter in the field). Data was recorded on grain yield and bi‐ omass at harvest. Selection at each generation was based only on biomass. High biomass types under both conditions were forwarded to next generation. In the next generation, one tiller from each plant was grown in PVC pipes to study root traits (Figure 3). All subsequent generations were forwarded in three places. Two in field (WW and drought) and one in PVC tubes. The se‐


MAS= Marker-assisted selection, PPB= Participatory plant breeding, ARB = Aerobic rice Bangalore

**Table 3.** Drought resistant lines/ list of varieties developed

In conclusion, breeding for drought resistance can do only as much as develop a genotype that can tolerate to moisture stress and respond to incremental water inputs should that be possible in the given habitat. The final answer to maximizing productivity comes from an integrated approach where genotype, agronomy, management, economics and policy come together to maximize the water productivity, the key limiting natural resource. Water is not equitably distributed in the world and the scarcity of water is assuming ominous dimensions (Figure 3).
